Functional oligomers and functional polymers including hydroxylated polymers and conjugates thereof and uses thereof

ABSTRACT

The present disclosure describes functional oligomers or functional polymers. The functional oligomers or functional polymers may contain functional groups, e.g., —OH and/or —CHO. The functional oligomers or functional polymers may be obtained from hydrolyzing certain copolymers and may be soluble in commercially available solvents. The copolymers may be thermosetting polymers. The functional oligomers and functional polymers may be useful for recycling thermosetting polymers and may be useful as starting materials for preparing additional oligomers or polymers.

RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application, U.S. Ser. No. 62/935,799, filed Nov. 15, 2019,which is incorporated herein by reference in its entirety.

GOVERNMENT SUPPORT

This invention was made with Government support under Grant No.CHE1629358 awarded by the National Science Foundation. The Governmenthas certain rights in the invention.

BACKGROUND OF THE INVENTION

Thermosets play a key role in the modern plastics and rubber industries,representing approximately 18% of current polymer material productionwith a worldwide annual production of 65 million tons. However, the highdensity of chemical crosslinks that give thermosets their usefulproperties (e.g., chemical/thermal resistance, and tensile strength)comes at the cost of limited opportunities for degradation andreprocessing (1, 2). As a consequence, the vast majority of currentlyproduced thermoset materials is incinerated or stored in landfillsfollowing use; a negligible fraction is repurposed or reused. Thus,novel thermoset reprocessing and upcycling strategies that canseamlessly integrate with existing manufacturing workflows could offertremendous opportunities to minimize plastic and rubber waste.

To date, perhaps the most widely studied strategies for enablingreprocessing of thermosets involve the use of dynamic covalent bondexchange reactions (3). For example, “vitrimers,” which are polymernetworks that undergo associative covalent bond exchange (e.g.,transesterification) upon heating and/or in the presence of a catalyst(4, 5), display many of the desirable properties of thermosets withadditional features such as moldability and dissolvability into smallercyclic fragments for re/upcycling. Nevertheless, commercially importanthigh-performance thermosets often lack appropriate bonding motifs forfacile conversion into vitrimers.

SUMMARY OF THE INVENTION

The present disclosure describes functional oligomers and functionalpolymers comprising:

i) one or more instances of linear units, wherein each instance of thelinear units is of the formula:

ii) one or more instances of functional units, wherein each instance ofthe functional units is independently of the formula:

iii) optionally one or more instances of crosslinking units, whereineach instance of the crosslinking units is of the formula:

and

iv) optionally one or more additional linear units, one or moreadditional terminal units, and/or one or more additional crosslinkingunits.

The present disclosure describes hydroxylated polymers prepared byhydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst:

i) one or more instances of a first monomer of the formula:

and

ii) one or more instances of a second monomer of Formula (B):

The present disclosure also describes conjugates prepared by reacting ahydroxy-reacting substance with a hydroxylated polymer. The presentdisclosure further describes methods of preparation, compositions, andkits.

The hydroxylated polymers may represent a new class of low-cost, denselyhydroxylated, alkene-functionalized hydrocarbon frameworks with numerouspotential opportunities for repurposing and/or upcyling (FIGS. 3c, 3d ).The size of the hydroxylated polymers may be readily tuned by modifyingthe molar ratio of the first monomer to the second monomer. Thehydroxylated polymers may be soluble (e.g., soluble in water at 1 atmand 20° C.). The hydroxylated polymers may be crosslinked.

The hydroxylated polymers may form conjugates by reacting with ahydroxy-reacting substance (e.g., hydroxy-reacting small molecule,hydroxy-reacting polymer). The mechanical properties of the conjugatesmay be better than those of the hydroxylated polymers and/or those ofthe hydroxy-reacting substance. The stability (e.g., physical stability,chemical stability) of the conjugates may be better than those of thehydroxylated polymers and/or those of the hydroxy-reacting substance.

In certain embodiments, the functional oligomer or functional isprepared by a method comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; and

iii) optionally one or more instances of a third monomer;

In certain embodiments, the functional oligomer or functional polymer isprepared by a method comprising polymerizing in the presence of ametathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; and

iii) optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

In certain embodiments, the functional oligomer or functional polymer isprepared by a method comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; and

iii) optionally one or more instances of a third monomer; The presentdisclosure also describes compounds of Formula (B1):

and salts thereof.

The present disclosure also describes copolymers prepared by a methodcomprising polymerizing:

one or more instances of a first monomer;

one or more instances of a second monomer, wherein the second monomer isa compound of Formula (B1), or a salt thereof; and

optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other;

in the presence of a metathesis catalyst.

The present disclosure also describes method of preparing copolymerscomprising polymerizing:

one or more instances of a first monomer;

one or more instances of a second monomer, wherein the second monomer isa compound of Formula (B1), or a salt thereof; and optionally one ormore instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other;

in the presence of a metathesis catalyst.

In certain embodiments, at least one instance of the first monomer is ofFormula:

or salt thereof.

Thermosetting polymers are typically difficult to be recycled. Thefunctional oligomers and functional polymers may be degradation (e.g.,hydrolysis) products of thermosetting polymers. The functional oligomersor functional polymers may contain functional groups, e.g., —OH and/or—CHO. The functional oligomers and functional polymers may be solublein, e.g., commercially available solvents (e.g., THF). The functionaloligomers and functional polymers may be useful for recyclingthermosetting polymers. The functional oligomers and functional polymersmay be useful as starting materials for preparing additional oligomersor polymers.

The details of certain embodiments of the invention are set forth in theDetailed Description of Certain Embodiments, as described below. Otherfeatures, objects, and advantages of the invention will be apparent fromthe Definitions, Figures, Examples, Clauses, and Claims. The aspectsdescribed herein are not limited to specific embodiments, methods,apparati, or configurations, and as such can, of course, vary. Theterminology used herein is for the purpose of describing particularaspects only and, unless specifically defined herein, is not intended tobe limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C. Precise placement of degradable bonds within polynorbornenestrands is crucial for degradation into soluble fragments at low monomerloadings. (FIG. 1A) The incorporation of silyl ethers withinpolynorbornene stands (with iPrSi) or between polynorbornene strands(with SiXL) are expected to yield dramatically different results. (FIG.1B) pDCPD doped with 20% v/v SiXL remains intact after 12 hour TBAFtreatment. (FIG. 1C) Shear rheology on THF-swollen samples shows a moredramatic TBAF-dependent loss in storage modulus for samples containingsmall amounts (2.5 vol % and 5 vol %) of iPrSi compared to 20 vol % ofSiXL, highlighting the greater contribution of cleavable strands tonetwork integrity. Samples were exposed to TBAF for 12 h at roomtemperature. Centre values denote average. Error bars denote s.e.m.; n=3for mass quantification, n=2-4 for rheology.

FIGS. 2A-2B. Functional evaluation of doped pDCPD (e.g., a copolymerdescribed herein). (FIG. 2A) Doped pDCPD shows no statisticallysignificant difference in modulus at low iPrSi loadings by dynamicmechanical analysis. (FIG. 2B) iPrSi doping results in increased carbonrelease in synthetic seawater. n.s.—P>0.1, *—P<0.05, **—P<0.01.

FIGS. 3A-3F. Soluble pDCPD fragments (e.g., a hydroxylated polymerdescribed herein) enable high-resolution characterization of the parentmaterial and can be functionalized and incorporated into new materials.(FIG. 3A) Comparison of ¹³C NMR spectra of pDCPD derived from CP-MAS orfrom analysis of soluble fragments after TBAF treatment. (FIG. 3B)High-resolution ¹³C NMR enables assignment and characterization ofpDCPD. (FIG. 3C) pDCPD fragments are poised for further modification andreprocessed into new materials. (FIG. 3D) TEM images of fragments beforePDMS modification. TEM images of fragments (stained with RuO4) derivedfrom 10 vol % iPrSi-pDCPD, showing an average particle size of ˜4 nm(FIG. 3E) Images of PDMS composites containing different weight percentsof pDCPD fragments. (FIG. 3F) Mechanical characterization of compositeswith or without 0.5 wt % pDCPD fragments. *—P<0.05, **—P<0.01.

FIG. 4. Full DMA traces from pDCPD samples containing different levelsof iPrSi.

FIG. 5. Representative nanoindentation traces from pDCPD samplescontaining different levels of iPrSi.

FIG. 6. Images of samples of pDCPD containing 0, 2.5, or 5% iPrSi,treated with TBAF for 12 hours or swollen in THF for 12 hours, thendried. Samples were sputter coated with AuPd alloy before He-ionimaging. Buckling of the THF-only samples is attributed to deformationsinduced by swelling and drying of the material. The 5% iPrSi sample,after TBAF treatment and drying, is significantly deformed (as evidencedin the 1 mm image). No microporosity was observed in any of TBAF-treatedsamples (no pores observed at 5 μm), consistent with full collapse ofthe partially degraded polymer networks upon solvent removal.

FIGS. 7A-7C. (FIG. 7A) Image of weathering setup. Samples were keptinside clear glass vials over the course of weathering. (FIG. 7B)Measured irradiance for samples during weathering experiments andcomparison to solar reference spectra. (FIG. 7C) Images of samplesbefore and after weathering, showing some bleaching of the material.

FIG. 8. Solution-phase COSY spectrum of the degradation solution derivedfrom 10% iPrSi doped pDCPD.

FIG. 9. Solution-phase NOESY spectrum of the degradation solution from10% iPrSi-doped pDCPD.

FIG. 10. Additional TEM images of fragments derived from 10% iPrSi-dopedpDCPD.

FIGS. 11A-11B. DOSY spectra confirming successful conjugation of PDMSand fragments derived from 10% iPrSi-doped pDCPD. Spectra of the (FIG.1A) Starting PDMS chloride and (FIG. 11B) fragments after PDMSconjugation show slower rates of diffusion for peaks in the PDMS region.

FIG. 12. DMA traces of unfilled PDMS and PDMS composites containing 0.5%w/w pDCPD fragments.

FIG. 13. Normalized GPC traces of pDCPD fragments before and after PLAgrowth.

FIGS. 14A-14B. (FIG. 14A) ¹H NMR and (FIG. 14B) DOSY spectra of pDCPDfragments after PLA growth.

FIG. 15. Normalized GPC traces of pDCPD fragments before and after PEGconjugation.

FIGS. 16A-16B. (FIG. 16A)¹H NMR and (FIG. 16B) DOSY spectra of pDCPDfragments after PEG conjugation.

FIGS. 17A-17D. (FIG. 17A) Schematic showing thermosets are oftensynthesized from the crosslinking of linear prepolymers with f crosslinkfunctionalities. The resulting materials can have outstandingproperties, but they often have unknown numbers of crosslinks (c) andthey are typically non-degradable/non-reprocessable. (FIG. 17B)Theoretical model describing the amount of cleavable monomer (x)relative to non-cleavable crosslinks (c) that will result in degradationof materials composed of strands of functionality f=3,000 into solubleproducts. (FIG. 17C) The silyl ether-based monomer iPrSi copolymerizesefficiently with norbornenes through ROMP, which introduces cleavablesilyl ether sites within the polynorbornene strands of pDCPD. Theintroduction of x cleavable bonds within the strands of pDCPD with ccrosslinks provides degradation fragments with (c/(x+1)) crosslinks perstrand. (FIG. 17D) The silyl ether crosslinker SiXL copolymerizes withnorbornenes through ROMP, but introduces cleavable silyl ether sitesbetween polynorbornene strands (that is, in crosslinks). Theintroduction of y cleavable crosslinks produces pDCPD with c+ycrosslinks. Thus, soluble products can only be generated when y>>c,suggesting that complete material degradation at low cleavablecrosslinker loadings will be difficult. stat, statistical copolymer.

FIGS. 18A-18B. Precise placement of a small number of degradable bondswithin the strands of pDCPD thermosets enables degradation into solubleproducts. (FIG. 18A) iPrSi-doped pDCPD samples show iPrSivolume-fraction-dependent dissolution in a THF solution of TBAF. Samplescontaining 10% or 15% iPrSi are almost entirely dissolved. (FIG. 18B)Quantification of residual mass of pDCPD samples after TBAF treatment atroom temperature for 12 h or 17 d for iPrSi- or SiXL-doped samples,respectively. The 7.5% and 10% iPrSi-doped samples show nearly completemass loss, whereas samples prepared with up to 80% of SiXL remainintact.

FIGS. 19A-19G. Functional evaluation of doped pDCPD. (FIG. 19A)iPrSi-doped pDCPD shows no significant difference in Young's modulus(measured at room temperature) between 0% and 10% iPrSi. The 33% and 50%iPrSi-doped samples are closer to or above their Tg value at roomtemperature (46±7° C. and 14±2° C., respectively), which explains theirdifferent tensile behaviours compared to that of native pDCPD. (FIG.19B) iPrSi-doped pDCPD shows no significant difference in strain atbreak at low iPrSi loadings. (FIG. 19C) Stress-strain curves obtained atroom temperature for iPrSi-doped pDCPD samples and native pDCPD,highlighting the similarity between the 10% iPrSi-doped sample andnative pDCPD, as well as the ability to control stress-strain behaviourwith comonomer loading. (FIG. 19D) iPrSi-doped pDCPD samples showcomparable reduced moduli to native pDCPD, as assessed bynanoindentation. (FIG. 19E) iPrSi-doped pDCPD shows similardecomposition temperatures as native pDCPD. (FIG. 19F). Representativeimage sequences of impact and rebound for 0% and 10% iPrSi-doped pDCPDimpacted by steel microparticles. (FIG. 19G) Coefficient of restitutionplots for 0% and 10% iPrSi-doped pDCPD. Positive, zero and negativecoefficients of restitution correspond to particle rebound, embedmentand film perforation, respectively. These results suggest that thecomonomer approach could enable optimization of degradation forapplications of interest. NS, not significant, P>0.1; *P<0.05; **P<0.01.Statistical significance determined through a Student's t-test. Centrevalues denote average. Error bars denote s.e.m. n=3 for the 0% and 10%samples, n=4 for the 20% sample, n=2 for the 33% sample and n=1 for the50% sample used for tensile testing, n=46-49 for the nanoindentationmeasurements, n=3 for DMA and n=3 for weathering experiments.

FIGS. 20A-20F. Soluble pDCPD fragments enable high-resolutioncharacterization of pDCPD and can be recycled into new materials. (FIG.20A) GPC traces of fragments derived from the dissolution of iPrSi-dopedpDCPD. As expected, increased iPrSi loading leads to smaller degradationproducts, as evidenced by increases in retention time. (FIG. 20B) Imagesof representative recycled and new pDCPD samples. Discolouration of therecycled sample is attributed to residual Ru from the first crosslinkingand degradation process. Samples prepared using fragments from the TBAFdissolution method (right). Samples prepared using fragments from theHF-pyridine dissolution method (left). (FIG. 20C) Stress-strain curvesfrom dogbone-shaped samples of new and recycled pDCPD, showingcomparable stress-strain curves with increased strain at break for therecycled samples. (FIG. 20D) Elastic moduli of native and recycledpDCPD, as assessed by DMA and tensile testing. (FIG. 20E) Carbon fibrerecovery from 10% iPrSi-doped pDCPD composites. Costly carbon fibrefiller is often unrecoverable from thermoset composites. The degradablecomonomer approach allows its recovery under mild conditions. (FIG. 20F)Raman spectra of pristine and recovered carbon fibres, suggesting nochemical damage to the carbon fibre material. Centre values denoteaverage. Error bars denote s.e.m; n=3 for all conditions. a.u.,arbitrary units.

FIG. 21. The reverse gel-point concept used to derive the model ofdegradable thermosets shown in FIG. 17B. (Top) A thermoset networkcontaining f potential crosslinks per strand, c actual crosslinks perstrand and x cleavable bonds within each strand may or may not bedegraded into soluble fragments after bond cleavage. A model thatdetermines whether the material will dissolve can be described as afunction of f, c and x (FIG. 17B). (Bottom) The reverse gel-pointconcept enables this model by assuming that the minimum x required toenable thermoset degradation for given c and f values corresponds to thevalue that will inhibit the gelation of degradation fragments derivedfrom strands with f potential crosslinking sites and x cleavable bonds.Existing gelation theories (Miller-Macosko and Flory-Stockmayer) wereused to solve for x, given f and c. Key to the reverse gel-point conceptis the assumption that the network structure formed by the crosslinkingof linear copolymer strands followed by cleavage of degradable bonds inthose strands is identical to the network formed by first cleaving thelinear copolymer strands and then crosslinking the resulting degradationproducts.

FIGS. 22A-22C. Characterization of pDCPD. (FIG. 22A) Images of pDCPDwith various amounts of iPrSi and without iPrSi. (FIG. 22B) Images ofpDCPD with and without 20 vol % SiXL. (FIG. 22C) pDCPD doped with up to80 vol % SiXL remains intact after 12 h of TBAF treatment.

FIGS. 23A-23C. Further quantification of the impact of silyl etherincorporation into pDCPD strands. (FIG. 23A) Samples containingdifferent amounts of iPrSi (0, 2.5, 5, 7.5 and vol %) were incubated in0.5 M TBAF in THF overnight, showing iPrSi-dependent degradation. (FIG.23B) Loss moduli for native pDCPD and 2.5% and 5% iPrSi-doped samplesbefore and after TBAF treatment, as measured by oscillatory rheology.The storage moduli are presented in FIG. 1C. (FIG. 23C) THF swellingratios (THF swollen mass divided by dry mass) for native pDCPD and 2.5%and 5% iPrSi-doped samples following TBAF treatment. Centre valuesdenote average. Error bars denote s.e.m. n=3 for all samples.

FIGS. 24A-24B. Characterization of mechanical and thermal properties ofiPrSi-doped pDCPD by DMA. (FIG. 24A) Tan-delta plots of pDCPD samples asa function of iPrSi incorporation. (FIG. 24B) Storage moduli collectedat T_(g)—60° C. for all samples. n=3 for all samples, except for 33%where n S.

FIGS. 25A-25D. Synthesis and degradation of EtSi- and iPrSi-doped pDCPD.(FIG. 25A) Structure of EtSi, which differs from iPrSi in terms of thealkyl substituents on the silyl ether group. The less stericallyhindered ethyl groups render this monomer more susceptible to cleavage.(FIG. 25B) Images of 10% EtSi- or iPrSi-doped pDCPD. (FIG. 25C) 10% EtSidissolves in 0.5 M TBAF in TH after 12 h. (FIG. 25D) Images of 10%EtSi-doped (left) and iPrSi-doped (right) pDCPD exposed to THFcontaining 15% concentrated aqueous HCl (12.1 N). The EtSi sample showsnoticeably more rapid degradation under these conditions as compared tothe iPrSi sample. Both samples are largely degraded within 12 h. In thiscase, acidic hydrolysis is facilitated by the presence of organicsolvent to swell the network.

FIGS. 26A-26B Weathering studies. (FIG. 26A) Measured irradiance forsamples during the weathering experiments and comparison to solarreference spectra (ASTM G177). (FIG. 26C) Ultraviolet-visiblespectra forthe 0%, 10% and 20% iPrSi- and 10% EtSi-doped pDCPD samples. The samplethickness was 1 mm.

FIG. 27. Schematic showing synthesis of cyclic acetals. This is inprinciple generalizablel to any low molecular weight acetal derivativethat can be purified by distillation.

FIG. 28. Results of GPC analysis. PEG-MM (DP=8) was copolymerized with0, 1, or 2 equivalents of acetal. After 30 minutes, the reaction wasquenched with EVE and analyzed by GPC. The material was concentratedunder vacuum for 30 minutes, then redissolved in THF containing 10% 2MHCl. The solution was stirred for 30 minutes, then dried over Na₂SO₄.The remaining material was then analyzed by GPC.

FIG. 29. GPC analysis of PEG Bottlebrush, DP=30, +/−HCl PEG Bottlebrush,DP=30, 1:1 PEG/iPrAc-7

+/−HCl

FIG. 30. GPC analysis of PEG Bottlebrush, DP=30, 1:1 PEG/iPrAc

+/−HCl

FIG. 31. GPC analysis of PEG Bottlebrush, DP=30, 1:1 PEG/iPrAc (M)+/−HCl

FIG. 32. GPC analysis of Acetal pDCPD: 7 vs. 8 Membered Acetals in pDCPD

FIGS. 33A-33B. ¹HNMR (FIG. 33A) and ¹³C NMR of fragments (FIG. 33B) frompDCPD with iPrAc.

FIG. 34. Dissolution of pDCPD with non silyl-ether comonomers.

FIG. 35. Images of pDCPD fragments with non silyl-ether comonomers.

FIG. 36. Schematic on generation of aldehyde-terminated pDCPD fragmentFIGS. 37A-37B. ¹HNMR of pDCPD fragments with aldehyde functional groups.Results of 5% (FIG. 37A) and 10% (FIG. 37B) DHF

in pDCPD are shown.

FIG. 38. ICP-OES data on solid 0% and 5% iPrSi doped pDCPD samplesbefore and after TBAF treatment. These results demonstrate that at least95% of the silyl ether groups in the material are cleaved under ourconditions. The residual silicon signal in the 0/sample, which isexpected to show no silicon in ICP-OES analysis in theory, is likelyderived from environmental sources of silicon such as the glass used toprepare and digest the material.

FIGS. 39A-39B. Dissolution of iPrSi doped pDCPD as a function of time.10% iPrSi doped pDCPD was incubated with TBAF at 1, 2, 4, or 8 hours inthe presence of 200 mol % TBAF. (FIG. 39A) Images of samples aftertreatment with TBAF for various times, followed by washing with THF toremove unreacted TBAF and to stop the reaction. (FIG. 39B)Quantification of residual solid mass as a percentage of initial samplemass. Minimal swelling of the material was visually observed, suggestingthat degradation of the material proceeds via surface erosion and thatdiffusion of TBAF into the material is rate-limiting.

FIG. 40. Frequency sweep rheology of THF swollen samples containing 20%v/v of SiXL FIG. 41. 10% iPrSi doped pDCPD readily dissolves in thepresence of hydrogen fluoride-pyridine complex in THF.

FIG. 42. iPrSi doped samples display distinct surface morphologiesfollowing exposure to aqueous NaOH as assessed by atomic forcemicroscopy, suggesting base-mediated etching of silyl ether groups atthe surface of the material.

FIG. 43. TEM images of organic extracts from weathering samples, showingthe presence of nanoparticles formed over the course of weathering.Scale bars are 10 nm for all images.

FIG. 44. Samples of pDCPD containing 10, 20, 33, and 50% iPrSi dissolvein the presence of 2 equivalents of TBAF in THF at room temperature.

FIG. 45. ¹H NMR (CDCl₃; 500 MHz.) of soluble fragments derived frommaterials with different amounts of hydroxyl groups, showing increasedlevels of silyl ether-derived fragments from pDCPD doped with moreiPrSi. In parentheses are the theoretical integration values assumingequal addition of equal volumes of the two materials. These results alsoindicate full consumption of the norbornene component of DCPD in ourmaterials, as the sharp peaks corresponding to unreacted DCPD areabsent.

FIG. 46. Full solution-phase ¹³C NMR spectra (CDCl₃; 500 MHz) of thedegradation solution, enabling characterization of crosslink densitywithin the parent pDCPD material.

FIG. 47. ¹³C NMR spectra (CDCl₃; 125 MHz) of pDCPD fragments withdifferent amounts of iPrSi doping.

FIG. 48. Solution-phase HSQC spectrum (CDCl₃; 500 MHz) of thedegradation solution derived from 10% iPrSi doped pDCPD.

FIG. 49. Solution-phase HMBC spectrum (CDCl₃; 500 MHz) of thedegradation solution derived from 10% iPrSi doped pDCPD.

FIG. 50. Comparison of ¹H NMR spectra (CDCl₃; 500 MHz/125 MHz) from ourpDCPD fragments and independently synthesized linear pDCPD. Linear pDCPDwas synthesized through the polymerization of DCPD with Schrock'sMo-catalyst (XiMo).

FIG. 51. ¹³C spectra comparing pDCPD fragments to linear pDCPD (CDCl₃;125 MHz).

FIG. 52. ¹³C spectra comparing pDCPD fragments to linear pDCPD (CDCl₃;125 MHz). ¹³C spectra, zoomed into the olefinic region, to highlightdifferences between pDCPD fragments and linear pDCPD. Some of thedifferences are assigned in the olefinic region to pDCPD crosslinks.

FIG. 53. DOSY spectrum (CDCl₃; 500 MHz) of the degradation solution frompDCPD doped with 10% iPrSi.

FIG. 54. DOSY spectrum (CDCl₃; 500 MHz) of the degradation solution frompDCPD doped with 20% iPrSi.

FIG. 55. DOSY spectrum (CDCl₃; 500 MHz) of the degradation solution frompDCPD doped with 33% iPrSi.

FIG. 56. DOSY spectrum (CDCl₃; 500 MHz) of the degradation solution frompDCPD doped with 50% iPrSi.

FIG. 57. DMA traces of recycled pDCPD (containing 25% pDCPD fragments).

FIG. 58. Images of SiXL-doped samples after treatment with TBAF for 17days.

FIG. 59. Frequency sweep rheology of THF swollen samples of degradedpDCPD samples showing decreasing moduli after TBAF treatment withincreasing iPrSi. In contrast, all three samples show similar moduli inthe absence of TBAF.

FIG. 60. Full stress-strain curves from pDCPD samples containingdifferent levels of iPrSi.

FIG. 61. A representative LIPIT image sequence from a 10% iPrSi-dopedpDCPD sample showing particle rebound.

FIG. 62. A representative LIPIT image sequence from a 10% iPrSi-dopedpDCPD sample showing particle embedment.

FIG. 63. A representative LIPIT image sequence from a 10% iPrSi-dopedpDCPD sample showing particle perforation.

DEFINITIONS

Definitions of specific functional groups and chemical terms aredescribed in more detail below. The chemical elements are identified inaccordance with the Periodic Table of the Elements, CAS version,Handbook of Chemistry and Physics, 75^(th)Ed., inside cover, andspecific functional groups are generally defined as described therein.Additionally, general principles of organic chemistry, as well asspecific functional moieties and reactivity, are described in ThomasSorrell, Organic Chemistry, University Science Books, Sausalito, 1999;Smith and March, March's Advanced Organic Chemistry, 5^(th) Edition,John Wiley & Sons, Inc., New York, 2001; Larock, Comprehensive OrganicTransformations, VCH Publishers, Inc., New York, 1989; and Carruthers,Some Modern Methods of Organic Synthesis, 3^(rd) Edition, CambridgeUniversity Press, Cambridge, 1987.

Compounds described herein can comprise one or more asymmetric centers,and thus can exist in various isomeric forms, e.g., enantiomers and/ordiastereomers. For example, the compounds described herein can be in theform of an individual enantiomer, diastereomer or geometric isomer, orcan be in the form of a mixture of stereoisomers, including racemicmixtures and mixtures enriched in one or more stereoisomer. Isomers canbe isolated from mixtures by methods known to those skilled in the art,including chiral high pressure liquid chromatography (HPLC),supercritical fluid chromatography (SFC), and the formation andcrystallization of chiral salts; or preferred isomers can be prepared byasymmetric syntheses. See, for example, Jacques et al., Enantiomers,Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen etal., Tetrahedron 33:2725 (1977); Eliel, Stereochemistry of CarbonCompounds (McGraw-Hill, N Y, 1962); and Wilen, Tables of ResolvingAgents and Optical Resolutionsp. 268 (E. L. Eliel, Ed., Univ. of NotreDame Press, Notre Dame, Ind. 1972). The present disclosure additionallyencompasses compounds described herein as individual isomerssubstantially free of other isomers, and alternatively, as mixtures ofvarious isomers.

In a formula, the bond

is a single bon, the dashed line - - - is a single bond or absent, andthe bond

or

is a single or double bond.

Unless otherwise provided, a formula depicted herein includes compoundsthat do not include isotopically enriched atoms and also compounds thatinclude isotopically enriched atoms. Compounds that include isotopicallyenriched atoms may be useful as, for example, analytical tools, and/orprobes in biological assays.

The term “aliphatic” includes both saturated and unsaturated,nonaromatic, straight chain (i.e., unbranched), branched, acyclic, andcyclic (i.e., carbocyclic) hydrocarbons. In some embodiments, analiphatic group is optionally substituted with one or more functionalgroups (e.g., halo, such as fluorine). As will be appreciated by one ofordinary skill in the art, “aliphatic” is intended herein to includealkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and cycloalkynylmoieties.

When a range of values (“range”) is listed, it is intended to encompasseach value and sub-range within the range. A range is inclusive of thevalues at the two ends of the range unless otherwise provided. Forexample, “an integer between 1 and 4” refers to 1, 2, 3, and 4. Forexample “C₁₋₆ alkyl” is intended to encompass, C₁, C₂, C₃, C₄, C₅, C₆,C₁₋₆, C₁₋₅, C₄, C₁₋₃, C₁₋₂, C₂₋₆, C₂₋₅, C₂₋₄, C₂₋₃, C₃₋₆, C₃₋₅, C₃₋₄,C₄₋₆, C₄₋₅, and C₅₋₆ alkyl.

“Alkyl” refers to a radical of a straight-chain or branched saturatedhydrocarbon group having from 1 to 20 carbon atoms (“C₁₋₂₀ alkyl”). Insome embodiments, an alkyl group has 1 to 12 carbon atoms (“C₁₋₆alkyl”). In some embodiments, an alkyl group has 1 to 10 carbon atoms(“C₁₋₁₀ alkyl”). In some embodiments, an alkyl group has 1 to 9 carbonatoms (“C₁₋₉ alkyl”). In some embodiments, an alkyl group has 1 to 8carbon atoms (“C₁₋₈ alkyl”). In some embodiments, an alkyl group has 1to 7 carbon atoms (“C-7 alkyl”). In some embodiments, an alkyl group has1 to 6 carbon atoms (“C₁₋₆ alkyl”). In some embodiments, an alkyl grouphas 1 to carbon atoms (“C₁₋₅ alkyl”). In some embodiments, an alkylgroup has 1 to 4 carbon atoms (“C₁₋₄ alkyl”). In some embodiments, analkyl group has 1 to 3 carbon atoms (“C₁₋₃ alkyl”). In some embodiments,an alkyl group has 1 to 2 carbon atoms (“C₁₋₂ alkyl”). In someembodiments, an alkyl group has 1 carbon atom (“C₁ alkyl”). In someembodiments, an alkyl group has 2 to 6 carbon atoms (“C₂₋₆ alkyl”).Examples of C₁₋₆ alkyl groups include methyl (C₁), ethyl (C₂), n-propyl(C₃), isopropyl (C₃), n-butyl (C₄), tert-butyl (C₄), sec-butyl (C₄),iso-butyl (C₄), n-pentyl (C₅), 3-pentanyl (C₅), amyl (C₅), neopentyl(C₅), 3-methyl-2-butanyl (C₅), tertiary amyl (C₅), and n-hexyl (C₆).Additional examples of alkyl groups include n-heptyl (C₇), n-octyl (C₈)and the like. Unless otherwise specified, each instance of an alkylgroup is independently optionally substituted, e.g., unsubstituted (an“unsubstituted alkyl”) or substituted (a “substituted alkyl”) with oneor more substituents. In certain embodiments, the alkyl group isunsubstituted C₁₋₁₂ alkyl (e.g., —CH₃(Me), unsubstituted ethyl (Et),unsubstituted propyl (Pr, e.g., unsubstituted n-propyl (n-Pr),unsubstituted isopropyl (i-Pr)), unsubstituted butyl (Bu, e.g.,unsubstituted n-butyl (n-Bu), unsubstituted tert-butyl (tert-Bu ort-Bu), unsubstituted sec-butyl (sec-Bu or s-Bu), unsubstituted isobutyl(i-Bu)). In certain embodiments, the alkyl group is substituted C₁₋₁₂alkyl (such as substituted C₁₋₆ alkyl, e.g., —CH₂F, —CHF₂, —CF₃,—CH₂CH₂F, —CH₂CHF₂, —CH₂CF₃, or benzyl (Bn)). The attachment point ofalkyl may be a single bond (e.g., as in —CH₃), double bond (e.g., as in═CH₂), or triple bond (e.g., as in —CH). The moieties ═CH₂ and —CH arealso alkyl.

In some embodiments, an alkyl group is substituted with one or morehalogens. “Perhaloalkyl” is a substituted alkyl group as defined hereinwherein all of the hydrogen atoms are independently replaced by ahalogen, e.g., fluoro, bromo, chloro, or iodo. In some embodiments, thealkyl moiety has 1 to 8 carbon atoms (“C₁₋₈ perhaloalkyl”). In someembodiments, the alkyl moiety has 1 to 6 carbon atoms (“C₁₋₆perhaloalkyl”). In some embodiments, the alkyl moiety has 1 to 4 carbonatoms (“C₁₋₄ perhaloalkyl”). In some embodiments, the alkyl moiety has 1to 3 carbon atoms (“C₁₋₃ perhaloalkyl”). In some embodiments, the alkylmoiety has 1 to 2 carbon atoms (“C₁₋₂ perhaloalkyl”). In someembodiments, all of the hydrogen atoms are replaced with fluoro. In someembodiments, all of the hydrogen atoms are replaced with chloro.Examples of perhaloalkyl groups include —CF₃, —CF₂CF₃, —CF₂CF₂CF₃,—CCl₃, —CFCl₂, —CF₂Cl, and the like.

“Alkenyl” refers to a radical of a straight-chain or branchedhydrocarbon group having from 2 to 20 carbon atoms, one or more (e.g.,two, three, or four, as valency permits) carbon-carbon double bonds, andno triple bonds (“C₂₋₂₀ alkenyl”). In some embodiments, an alkenyl grouphas 2 to 10 carbon atoms (“C₂₋₁₀ alkenyl”). In some embodiments, analkenyl group has 2 to 9 carbon atoms (“C₂₋₉ alkenyl”). In someembodiments, an alkenyl group has 2 to 8 carbon atoms (“C₂₋₈ alkenyl”).In some embodiments, an alkenyl group has 2 to 7 carbon atoms (“C₂₋₇alkenyl”). In some embodiments, an alkenyl group has 2 to 6 carbon atoms(“C₂₋₅ alkenyl”). In some embodiments, an alkenyl group has 2 to 5carbon atoms (“C₂₋₅ alkenyl”). In some embodiments, an alkenyl group has2 to 4 carbon atoms (“C₂₋₄ alkenyl”). In some embodiments, an alkenylgroup has 2 to 3 carbon atoms (“C₂₋₃ alkenyl”). In some embodiments, analkenyl group has 2 carbon atoms (“C₂ alkenyl”). The one or morecarbon-carbon double bonds can be internal (such as in 2-butenyl) orterminal (such as in 1-butenyl). Examples of C₂₋₄ alkenyl groups includeethenyl (C₂), 1-propenyl (C₃), 2-propenyl (C₃), 1-butenyl (C₄),2-butenyl (C₄), butadienyl (C₄), and the like. Examples of C₂₋₆ alkenylgroups include the aforementioned C₂₋₄ alkenyl groups as well aspentenyl (C₅), pentadienyl (C₅), hexenyl (C₆), and the like. Additionalexamples of alkenyl include heptenyl (C₇), octenyl (C₈), octatrienyl(C₈), and the like. Unless otherwise specified, each instance of analkenyl group is independently optionally substituted, e.g.,unsubstituted (an “unsubstituted alkenyl”) or substituted (a“substituted alkenyl”) with one or more substituents. In certainembodiments, the alkenyl group is unsubstituted C₂₋₁₀ alkenyl. Incertain embodiments, the alkenyl group is substituted C₂₋₁₀ alkenyl. Inan alkenyl group, a C═C double bond for which the stereochemistry is notspecified (e.g., —CH═CHCH₃ or

may be in the (E)- or (Z)-configuration.

“Alkynyl” refers to a radical of a straight-chain or branchedhydrocarbon group having from 2 to 20 carbon atoms, one or more (e.g.,two, three, or four, as valency permits) carbon-carbon triple bonds, andoptionally one or more double bonds (“C₂₋₂₀ alkynyl”). In someembodiments, an alkynyl group has 2 to 10 carbon atoms (“C₂₋₁₀alkynyl”). In some embodiments, an alkynyl group has 2 to 9 carbon atoms(“C₂₋₉ alkynyl”). In some embodiments, an alkynyl group has 2 to 8carbon atoms (“C₂₋₈ alkynyl”). In some embodiments, an alkynyl group has2 to 7 carbon atoms (“C₂₋₇ alkynyl”). In some embodiments, an alkynylgroup has 2 to 6 carbon atoms (“C₂₋₆ alkynyl”). In some embodiments, analkynyl group has 2 to 5 carbon atoms (“C₂₋₅ alkynyl”). In someembodiments, an alkynyl group has 2 to 4 carbon atoms (“C₂₋₄ alkynyl”).In some embodiments, an alkynyl group has 2 to 3 carbon atoms (“C₂₋₃alkynyl”). In some embodiments, an alkynyl group has 2 carbon atoms (“C₂alkynyl”). The one or more carbon-carbon triple bonds can be internal(such as in 2-butynyl) or terminal (such as in 1-butynyl). Examples ofC₂₋₄ alkynyl groups include ethynyl (C₂), 1-propynyl (C₃), 2-propynyl(C₃), 1-butynyl (C₄), 2-butynyl (C₄), and the like. Examples of C₂₋₆alkenyl groups include the aforementioned C₂₋₄ alkynyl groups as well aspentynyl (C₅), hexynyl (C₆), and the like. Additional examples ofalkynyl include heptynyl (C₇), octynyl (C₈), and the like. Unlessotherwise specified, each instance of an alkynyl group is independentlyoptionally substituted, e.g., unsubstituted (an “unsubstituted alkynyl”)or substituted (a “substituted alkynyl”) with one or more substituents.In certain embodiments, the alkynyl group is unsubstituted C₂₋₁₀alkynyl. In certain embodiments, the alkynyl group is substituted C₂₋₁₀alkynyl.

“Carbocyclyl” or “carbocyclic” refers to a radical of a non-aromaticcyclic hydrocarbon group having from 3 to 13 ring carbon atoms (“C₃₋₁₃carbocyclyl”) and zero heteroatoms in the non-aromatic ring system. Insome embodiments, a carbocyclyl group has 3 to 8 ring carbon atoms(“C₃₋₈ carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to7 ring carbon atoms (“C₃₋₇ carbocyclyl”). In some embodiments, acarbocyclyl group has 3 to 6 ring carbon atoms (“C₃₋₆ carbocyclyl”). Insome embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms(“C₅₋₁₀ carbocyclyl”). Exemplary C₃₋₆ carbocyclyl groups includecyclopropyl (C₃), cyclopropenyl (C₃), cyclobutyl (C₄), cyclobutenyl(C₄), cyclopentyl (C₅), cyclopentenyl (C₅), cyclohexyl (C₆),cyclohexenyl (C₆), cyclohexadienyl (C₆), and the like. Exemplary C₃₋₈carbocyclyl groups include the aforementioned C₃₋₆ carbocyclyl groups aswell as cycloheptyl (C₇), cycloheptenyl (C₇), cycloheptadienyl (C₇),cycloheptatrienyl (C₇), cyclooctyl (C₈), cyclooctenyl (C₈),bicyclo[2.2.1]heptanyl (C₇), bicyclo[2.2.2]octanyl (C₈), and the like.Exemplary C₃₋₁₀ carbocyclyl groups include the aforementioned C₃₋₈carbocyclyl groups as well as cyclononyl (C₉), cyclononenyl (C₉),cyclodecyl (C₁₀), cyclodecenyl (C₁₀), octahydro-1H-indenyl (C₉),decahydronaphthalenyl (C₁₀), spiro[4.5]decanyl (C₁₀), and the like. Asthe foregoing examples illustrate, in certain embodiments, thecarbocyclyl group is either monocyclic (“monocyclic carbocyclyl”) orcontain a fused, bridged, or spiro ring system such as a bicyclic system(“bicyclic carbocyclyl”). Carbocyclyl can be saturated, and saturatedcarbocyclyl is referred to as “cycloalkyl.” In some embodiments,carbocyclyl is a monocyclic, saturated carbocyclyl group having from 3to 10 ring carbon atoms (“C₃₋₁₀ cycloalkyl”). In some embodiments, acycloalkyl group has 3 to 8 ring carbon atoms (“C₃₋₈ cycloalkyl”). Insome embodiments, a cycloalkyl group has 3 to 6 ring carbon atoms (“C₃₋₆cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 6 ringcarbon atoms (“C₅₋₆ cycloalkyl”). In some embodiments, a cycloalkylgroup has 5 to 10 ring carbon atoms (“C₅₋₁₀ cycloalkyl”). Examples ofC₅₋₆ cycloalkyl groups include cyclopentyl (C₅) and cyclohexyl (C₅).Examples of C₃₋₆ cycloalkyl groups include the aforementioned C₅₋₆cycloalkyl groups as well as cyclopropyl (C₃) and cyclobutyl (C₄).Examples of C₃₋₈ cycloalkyl groups include the aforementioned C₃₋₆cycloalkyl groups as well as cycloheptyl (C₇) and cyclooctyl (C₈).Unless otherwise specified, each instance of a cycloalkyl group isindependently unsubstituted (an “unsubstituted cycloalkyl”) orsubstituted (a “substituted cycloalkyl”) with one or more substituents.In certain embodiments, the cycloalkyl group is unsubstituted C₃₋₁₀cycloalkyl. In certain embodiments, the cycloalkyl group is substitutedC₃₋₁₀ cycloalkyl. Carbocyclyl can be partially unsaturated. Carbocyclylmay include zero, one, or more (e.g., two, three, or four, as valencypermits) C═C double bonds in all the rings of the carbocyclic ringsystem that are not aromatic or heteroaromatic. Carbocyclyl includingone or more (e.g., two or three, as valency permits) C═C double bonds inthe carbocyclic ring is referred to as “cycloalkenyl.” Carbocyclylincluding one or more (e.g., two or three, as valency permits) C═Ctriple bonds in the carbocyclic ring is referred to as “cycloalkynyl.”Carbocyclyl includes aryl. “Carbocyclyl” also includes ring systemswherein the carbocyclyl ring, as defined above, is fused with one ormore aryl or heteroaryl groups wherein the point of attachment is on thecarbocyclyl ring, and in such instances, the number of carbons continueto designate the number of carbons in the carbocyclic ring system.Unless otherwise specified, each instance of a carbocyclyl group isindependently optionally substituted, e.g., unsubstituted (an“unsubstituted carbocyclyl”) or substituted (a “substitutedcarbocyclyl”) with one or more substituents. In certain embodiments, thecarbocyclyl group is unsubstituted C₃₋₁₀ carbocyclyl. In certainembodiments, the carbocyclyl group is a substituted C₃₋₁₀ carbocyclyl.In certain embodiments, the carbocyclyl is substituted or unsubstituted,3- to 7-membered, and monocyclic. In certain embodiments, thecarbocyclyl is substituted or unsubstituted, 5- to 13-membered, andbicyclic.

In some embodiments, “carbocyclyl” is a monocyclic, saturatedcarbocyclyl group having from 3 to 10 ring carbon atoms (“C₃₋₁₀cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 8 ringcarbon atoms (“C₃₋₈ cycloalkyl”). In some embodiments, a cycloalkylgroup has 3 to 6 ring carbon atoms (“C₃₋₆ cycloalkyl”). In someembodiments, a cycloalkyl group has 5 to 6 ring carbon atoms (“C₅₋₆cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 10 ringcarbon atoms (“C₅₋₁₀ cycloalkyl”). Examples of C₅₋₆ cycloalkyl groupsinclude cyclopentyl (C₅) and cyclohexyl (C₅). Examples of C₃₋₆cycloalkyl groups include the aforementioned C₅₋₆ cycloalkyl groups aswell as cyclopropyl (C₃) and cyclobutyl (C₄). Examples of C₃₋₈cycloalkyl groups include the aforementioned C₃₋₆ cycloalkyl groups aswell as cycloheptyl (C₇) and cyclooctyl (C₈). Unless otherwisespecified, each instance of a cycloalkyl group is independentlyunsubstituted (an “unsubstituted cycloalkyl”) or substituted (a“substituted cycloalkyl”) with one or more substituents. In certainembodiments, the cycloalkyl group is unsubstituted C₃₋₁₀ cycloalkyl. Incertain embodiments, the cycloalkyl group is substituted C₃₋₁₀cycloalkyl.

“Heterocyclyl” or “heterocyclic” refers to a radical of a 3- to13-membered non-aromatic ring system having ring carbon atoms and 1 to 4ring heteroatoms, wherein each heteroatom is independently selected fromnitrogen, oxygen, and sulfur (“3-13 membered heterocyclyl”). Inheterocyclyl groups that contain one or more nitrogen atoms, the pointof attachment can be a carbon or nitrogen atom, as valency permits. Aheterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”)or a fused, bridged, or spiro ring system such as a bicyclic system(“bicyclic heterocyclyl”). A heterocyclyl group can be saturated or canbe partially unsaturated. Heterocyclyl may include zero, one, or more(e.g., two, three, or four, as valency permits) double bonds in all therings of the heterocyclic ring system that are not aromatic orheteroaromatic. Partially unsaturated heterocyclyl groups includesheteroaryl. Heterocyclyl bicyclic ring systems can include one or moreheteroatoms in one or both rings. “Heterocyclyl” also includes ringsystems wherein the heterocyclyl ring, as defined above, is fused withone or more carbocyclyl groups wherein the point of attachment is eitheron the carbocyclyl or heterocyclyl ring, or ring systems wherein theheterocyclyl ring, as defined above, is fused with one or more aryl orheteroaryl groups, wherein the point of attachment is on theheterocyclyl ring, and in such instances, the number of ring memberscontinue to designate the number of ring members in the heterocyclylring system. Unless otherwise specified, each instance of heterocyclylis independently optionally substituted, e.g., unsubstituted (an“unsubstituted heterocyclyl”) or substituted (a “substitutedheterocyclyl”) with one or more substituents. In certain embodiments,the heterocyclyl group is unsubstituted 3-10 membered heterocyclyl. Incertain embodiments, the heterocyclyl group is substituted 3-10 memberedheterocyclyl. In certain embodiments, the heterocyclyl is substituted orunsubstituted, 3- to 7-membered, and monocyclic. In certain embodiments,the heterocyclyl is substituted or unsubstituted, 5- to 13-membered, andbicyclic.

In some embodiments, a heterocyclyl group is a 5-10 memberednon-aromatic ring system having ring carbon atoms and 1-4 ringheteroatoms, wherein each heteroatom is independently selected fromnitrogen, oxygen, and sulfur (“5-10 membered heterocyclyl”). In someembodiments, a heterocyclyl group is a 5-8 membered non-aromatic ringsystem having ring carbon atoms and 1-4 ring heteroatoms, wherein eachheteroatom is independently selected from nitrogen, oxygen, and sulfur(“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl groupis a 5-6 membered non-aromatic ring system having ring carbon atoms and1-4 ring heteroatoms, wherein each heteroatom is independently selectedfrom nitrogen, oxygen, and sulfur (“5-6 membered heterocyclyl”). In someembodiments, the 5-6 membered heterocyclyl has 1-3 ring heteroatomsselected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6membered heterocyclyl has 1-2 ring heteroatoms selected from nitrogen,oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclylhas one ring heteroatom selected from nitrogen, oxygen, and sulfur.

Exemplary 3-membered heterocyclyl groups containing one heteroatominclude azirdinyl, oxiranyl, or thiiranyl. Exemplary 4-memberedheterocyclyl groups containing one heteroatom include azetidinyl,oxetanyl and thietanyl. Exemplary 5-membered heterocyclyl groupscontaining one heteroatom include tetrahydrofuranyl, dihydrofuranyl,tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyland pyrrolyl-2,5-dione. Exemplary 5-membered heterocyclyl groupscontaining two heteroatoms include dioxolanyl, oxasulfuranyl,disulfuranyl, and oxazolidin-2-one. Exemplary 5-membered heterocyclylgroups containing three heteroatoms include triazolinyl, oxadiazolinyl,and thiadiazolinyl. Exemplary 6-membered heterocyclyl groups containingone heteroatom include piperidinyl, tetrahydropyranyl, dihydropyridinyl,and thianyl. Exemplary 6-membered heterocyclyl groups containing twoheteroatoms include piperazinyl, morpholinyl, dithianyl, and dioxanyl.Exemplary 6-membered heterocyclyl groups containing two heteroatomsinclude triazinanyl. Exemplary 7-membered heterocyclyl groups containingone heteroatom include azepanyl, oxepanyl and thiepanyl. Exemplary8-membered heterocyclyl groups containing one heteroatom includeazocanyl, oxecanyl, and thiocanyl. Exemplary 5-membered heterocyclylgroups fused to a C₆ aryl ring (also referred to herein as a5,6-bicyclic heterocyclic ring) include indolinyl, isoindolinyl,dihydrobenzofuranyl, dihydrobenzothienyl, benzoxazolinonyl, and thelike. Exemplary 6-membered heterocyclyl groups fused to an aryl ring(also referred to herein as a 6,6-bicyclic heterocyclic ring) includetetrahydroquinolinyl, tetrahydroisoquinolinyl, and the like.

“Aryl” refers to a radical of a monocyclic or polycyclic (e.g., bicyclicor tricyclic) 4n+2 aromatic ring system (e.g, having 6, 10, or 14 πelectrons shared in a cyclic array) having 6-14 ring carbon atoms andzero heteroatoms provided in the aromatic ring system (“C₆₋₁₄ aryl”). Insome embodiments, an aryl group has six ring carbon atoms (“C₆ aryl”;e.g., phenyl). In some embodiments, an aryl group has ten ring carbonatoms (“C₁₀ aryl”; e.g., naphthyl such as 1-naphthyl and 2-naphthyl). Insome embodiments, an aryl group has fourteen ring carbon atoms (“C₁₄aryl”; e.g., anthracyl). “Aryl” also includes ring systems wherein thearyl ring, as defined above, is fused with one or more carbocyclyl orheterocyclyl groups wherein the radical or point of attachment is on thearyl ring, and in such instances, the number of carbon atoms continue todesignate the number of carbon atoms in the aryl ring system. Unlessotherwise specified, each instance of an aryl group is independentlyoptionally substituted, e.g., unsubstituted (an “unsubstituted aryl”) orsubstituted (a “substituted aryl”) with one or more substituents. Incertain embodiments, the aryl group is unsubstituted C₆₋₁₄ aryl. Incertain embodiments, the aryl group is substituted C₆₋₁₄ aryl.

“Heteroaryl” refers to a radical of a 5-10 membered monocyclic orbicyclic 4n+2 aromatic ring system (e.g., having 6 or 10 π electronsshared in a cyclic array) having ring carbon atoms and 1-4 ringheteroatoms provided in the aromatic ring system, wherein eachheteroatom is independently selected from nitrogen, oxygen and sulfur(“5-10 membered heteroaryl”). In heteroaryl groups that contain one ormore nitrogen atoms, the point of attachment can be a carbon or nitrogenatom, as valency permits. Heteroaryl bicyclic ring systems can includeone or more heteroatoms in one or both rings. “Heteroaryl” includes ringsystems wherein the heteroaryl ring, as defined above, is fused with oneor more carbocyclyl or heterocyclyl groups wherein the point ofattachment is on the heteroaryl ring, and in such instances, the numberof ring members continue to designate the number of ring members in theheteroaryl ring system. “Heteroaryl” also includes ring systems whereinthe heteroaryl ring, as defined above, is fused with one or more arylgroups wherein the point of attachment is either on the aryl orheteroaryl ring, and in such instances, the number of ring membersdesignates the number of ring members in the fused (aryl/heteroaryl)ring system. Bicyclic heteroaryl groups wherein one ring does notcontain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and thelike) the point of attachment can be on either ring, e.g., either thering bearing a heteroatom (e.g., 2-indolyl) or the ring that does notcontain a heteroatom (e.g., 5-indolyl).

In some embodiments, a heteroaryl group is a 5-10 membered aromatic ringsystem having ring carbon atoms and 1-4 ring heteroatoms provided in thearomatic ring system, wherein each heteroatom is independently selectedfrom nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In someembodiments, a heteroaryl group is a 5-8 membered aromatic ring systemhaving ring carbon atoms and 1-4 ring heteroatoms provided in thearomatic ring system, wherein each heteroatom is independently selectedfrom nitrogen, oxygen, and sulfur (“5-8 membered heteroaryl”). In someembodiments, a heteroaryl group is a 5-6 membered aromatic ring systemhaving ring carbon atoms and 1-4 ring heteroatoms provided in thearomatic ring system, wherein each heteroatom is independently selectedfrom nitrogen, oxygen, and sulfur (“5-6 membered heteroaryl”). In someembodiments, the 5-6 membered heteroaryl has 1-3 ring heteroatomsselected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6membered heteroaryl has 1-2 ring heteroatoms selected from nitrogen,oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has1 ring heteroatom selected from nitrogen, oxygen, and sulfur. Unlessotherwise specified, each instance of a heteroaryl group isindependently optionally substituted, e.g., unsubstituted(“unsubstituted heteroaryl”) or substituted (“substituted heteroaryl”)with one or more substituents. In certain embodiments, the heteroarylgroup is unsubstituted 5-14 membered heteroaryl. In certain embodiments,the heteroaryl group is substituted 5-14 membered heteroaryl.

Exemplary 5-membered heteroaryl groups containing one heteroatom includepyrrolyl, furanyl and thiophenyl. Exemplary 5-membered heteroaryl groupscontaining two heteroatoms include imidazolyl, pyrazolyl, oxazolyl,isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5-membered heteroarylgroups containing three heteroatoms include triazolyl, oxadiazolyl, andthiadiazolyl. Exemplary 5-membered heteroaryl groups containing fourheteroatoms include tetrazolyl. Exemplary 6-membered heteroaryl groupscontaining one heteroatom include pyridinyl. Exemplary 6-memberedheteroaryl groups containing two heteroatoms include pyridazinyl,pyrimidinyl, and pyrazinyl. Exemplary 6-membered heteroaryl groupscontaining three or four heteroatoms include triazinyl and tetrazinyl,respectively. Exemplary 7-membered heteroaryl groups containing oneheteroatom include azepinyl, oxepinyl, and thiepinyl. Exemplary5,6-bicyclic heteroaryl groups include indolyl, isoindolyl, indazolyl,benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl,benzoisofuranyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl,benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl,indolizinyl, and purinyl. Exemplary 6,6-bicyclic heteroaryl groupsinclude naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl,cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl.

“Partially unsaturated” refers to a group that includes at least onedouble or triple bond. The term “partially unsaturated” is intended toencompass rings having multiple sites of unsaturation, but is notintended to include aromatic groups (e.g., aryl or heteroaryl groups) asherein defined. Likewise, “saturated” refers to a group that does notcontain a double or triple bond, i.e., contains all single bonds.

In some embodiments, aliphatic, alkyl, alkenyl, alkynyl, carbocyclyl,heterocyclyl, aryl, and heteroaryl groups, as defined herein, areoptionally substituted (e.g., “substituted” or “unsubstituted” alkyl,“substituted” or “unsubstituted” alkenyl, “substituted” or“unsubstituted” alkynyl, “substituted” or “unsubstituted” carbocyclyl,“substituted” or “unsubstituted” heterocyclyl, “substituted” or“unsubstituted” aryl or “substituted” or “unsubstituted” heteroarylgroup). In general, the term “substituted”, whether preceded by the term“optionally” or not, means that at least one hydrogen present on a group(e.g., a carbon or nitrogen atom) is replaced with a permissiblesubstituent, e.g., a substituent which upon substitution results in astable compound, e.g., a compound which does not spontaneously undergotransformation such as by rearrangement, cyclization, elimination, orother reaction. Unless otherwise indicated, a “substituted” group has asubstituent at one or more substitutable positions of the group, andwhen more than one position in any given structure is substituted, thesubstituent is either the same or different at each position. The term“substituted” is contemplated to include substitution with allpermissible substituents of organic compounds, any of the substituentsdescribed herein that results in the formation of a stable compound. Thepresent disclosure contemplates any and all such combinations in orderto arrive at a stable compound. For purposes of this disclosure,heteroatoms such as nitrogen may have hydrogen substituents and/or anysuitable substituent as described herein which satisfy the valencies ofthe heteroatoms and results in the formation of a stable moiety.

Exemplary carbon atom substituents include halogen, —CN, —NO₂, —N₃,—SO₂, —SO₃H, —OH, —OR^(aa), —ON(R^(bb))₂, —N(R^(bb))₂, —N(R^(bb))₃ ⁺X⁻,—N(OR^(cc))R^(bb), —SH, —SR^(aa), —SSR^(cc), —C(═O)R^(aa), —CO₂H, —CHO,—C(OR)₂, —CO₂R^(aa), —OC(═O)R^(aa), —OCO₂R^(aa), —C(═O)N(R^(bb))₂,—OC(═O)N(R^(bb))₂, —NR^(bb)C(═O)R^(aa), —NR^(bb)CO₂R^(aa),—NR^(bb)C(═O)N(R^(bb))₂, —C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa),—OC(═NR^(bb))R^(aa), —OC(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂,—OC(═NR^(bb))N(R^(bb))₂, —NR^(bb)C(═NR^(bb))N(R^(bb))₂,—C(═O)NR^(bb)SO₂R^(aa), —NR^(bb)SO₂R^(aa), —SO₂N(R^(bb))₂, —SO₂R^(aa),—SO₂OR^(aa), —OSO₂R^(aa), —S(═O)R^(aa), —OS(═O)R^(aa), —Si(R^(aa))₃,—OSi(R^(aa))₃, —C(═S)N(R^(bb))₂, —C(═O)SR^(aa), —C(═S)SR^(aa),—SC(═S)SR^(aa), —SC(═O)SR^(aa), —OC(═O)SR^(aa), —SC(═O)OR^(aa),—SC(═O)R^(aa), —P(═O)(R^(aa))₂, —P(═O)(OR^(cc))₂, —OP(═O)(R^(aa))₂,—OP(═O)(OR^(cc))₂, —P(═O)(N(R^(bb))₂)₂, —OP(═O)(N(R^(bb))₂)₂,—NR^(bb)P(═O)(R^(aa))₂, —NR^(bb)P(═O)(OR^(cc))₂,—NR^(bb)P(═O)(N(R^(bb))₂)₂, —P(R^(cc))₂, —P(OR^(cc))₂, —P(R^(cc))₃ ⁺X⁻,—P(OR^(cc))₃ ⁺X⁻, —P(R^(cc))₄, —P(OR^(cc))₄, —OP(R^(cc))₂, —OP(R^(cc))₃⁺X⁻, —OP(OR^(cc))₂, —OP(OR^(cc))₃ ⁺X⁻, —OP(R^(cc))₄, —OP(OR^(cc))₄,—B(R^(aa))₂, —B(OR^(cc))₂, —BR(OR^(cc)), C₁₋₁₀ alkyl, C₁₋₁₀perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, heteroC₁₋₁₀ alkyl,heteroC₂₋₁₀ alkenyl, heteroC₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, whereineach alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 R groups; wherein X⁻ is acounterion;

or two geminal hydrogens on a carbon atom are replaced with the group═O, ═S, ═NN(R^(bb))₂, ═NNR^(bb)C(═O)R^(aa), ═NNR^(bb)C(═O)OR^(aa),═NNR^(bb)S(═O)₂R^(aa), ═NR^(bb), or ═NOR^(cc);

each instance of R^(aa) is, independently, selected from C₁₋₁₀ alkyl,C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, heteroC₁₋₁₀ alkyl,heteroC₂₋₁₀ alkenyl, heteroC₂₋₁₀alkynyl, C₃₋₁₀ carbocyclyl, 3-14membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or twoR^(aa) groups are joined to form a 3-14 membered heterocyclyl or 5-14membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl,heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl,aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or5 R^(dd) groups;

each instance of R^(bb) is, independently, selected from hydrogen, —OH,—OR^(aa), —N(R^(cc))₂, —CN, —C(═O)R^(aa), —C(═O)N(R^(cc))₂, —CO₂R^(aa),—SO₂R^(aa), —C(═NR^(cc))OR^(aa), —C(═NR^(cc))N(R^(cc))₂, —SO₂N(R^(cc))₂,—SO₂R^(cc), —SO₂OR^(cc), —SOR^(aa), —C(═S)N(R^(cc))₂, —C(═O)SR^(cc),—C(═S)SR^(cc), —P(═O)(R^(aa))₂, —P(═O)(OR^(cc))₂, —P(═O)(N(R^(cc))₂)₂,C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl,heteroC₁₋₁₀alkyl, heteroC₂₋₁₀alkenyl, heteroC₂₋₁₀alkynyl, C₃₋₁₀carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 memberedheteroaryl, or two R^(b) groups are joined to form a 3-14 memberedheterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl,alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups; wherein X⁻ is acounterion;

each instance of R^(cc) is, independently, selected from hydrogen, C₁₋₁₀alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, heteroC₁₋₁₀alkyl, heteroC₂₋₁₀ alkenyl, heteroC₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or twoR^(cc) groups are joined to form a 3-14 membered heterocyclyl or 5-14membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl,heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl,aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or5 R^(dd) groups:

each instance of R^(dd) is, independently, selected from halogen, —CN,—NO₂, —N₃, —SO₂H, —SO₃H, —OH, —OR^(ee), —ON(R^(ff))₂, —N(R^(ff))₂,—N(R^(ff))₃ ⁺X⁻, —N(OR^(ee))R^(ff), —SH, —SR^(ee), —SSR^(ee),—C(═O)R^(ee), —CO₂H, —CO₂R^(ee), —OC(═O)R^(ee), —OCO₂R^(ee),—C(═O)N(R^(ff))₂, —OC(═O)N(R^(ff))₂, —NR^(ff)C(═O)R^(ee),—NR^(ff)CO₂R^(ee), —NR^(ff)C(═O)N(R^(ff))₂, —C(═NR^(ff))OR^(ee),—OC(═NR^(ff))R^(ee), —OC(═NR^(ff))OR^(ee), —C(═NR^(ff))N(R^(ff))₂,—OC(═NR^(ff))N(R^(ff))₂, —NR^(ff)C(═NR^(ff))N(R^(ff))₂,—NR^(ff)SO₂R^(ee), —SO₂N(R^(ff))₂, —SO₂R^(ee), —SO₂OR^(ee), —OSO₂R^(ee),—S(═O)R^(ee), —Si(R^(ee))₃, —OSi(R^(ee))₃, —C(═S)N(R^(ff))₂,—C(═O)SR^(ee), —C(═S)SR^(ee), —SC(═S)SR^(ee), —P(═O)(OR^(ee))₂,—P(═O)(R^(ee))₂, —OP(═O)(R^(ee))₂, —OP(═O)(OR^(ee))₂, C₁₋₄ alkyl, C₁₋₆perhaloalkyl, C₂₋₆, alkenyl, C₂₋₆ alkynyl, heteroC₁₋₆alkyl,heteroC₂₋₆alkenyl, heteroC₂₋₆alkynyl, C₃₋₁₀ carbocyclyl, 3-10 memberedheterocyclyl, C₆₋₁₀ aryl, 5-10 membered heteroaryl, wherein each alkyl,alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 R^(gg) groups, or two geminalR^(dd) substituents can be joined to form ═O or ═S; wherein X⁻ is acounterion;

each instance of R^(ee) is, independently, selected from C₁₋₆ alkyl,C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₄, alkynyl, heteroC₁₋₆ alkyl,heteroC₂₋₆alkenyl, heteroC₂₋₆ alkynyl, C₃₋₁₀ carbocyclyl, C₆₋₁₀ aryl,3-10 membered heterocyclyl, and 3-10 membered heteroaryl, wherein eachalkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 R⁹ groups;

each instance of R^(ff) is, independently, selected from hydrogen, C₁₋₆alkyl, C₁₋₆ perhaloalkyl, C₂₋₄ alkenyl, C₂₋₆ alkynyl, heteroC₁₋₆alkyl,heteroC₂₋₆alkenyl, heteroC₂₋₆alkynyl, C₃₋₁₀ carbocyclyl, 3-10 memberedheterocyclyl, C₆₋₁₀ aryl and 5-10 membered heteroaryl, or two R^(ff)groups are joined to form a 3-10 membered heterocyclyl or 5-10 memberedheteroaryl ring, wherein each alkyl, alkenyl, alkynyl, heteroalkyl,heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, andheteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R⁹groups; and

each instance of R^(gg) is, independently, halogen, —CN, —NO₂, —N₃,—SO₂H, —SO₃H, —OH, —OC₁₋₆ alkyl, —ON(C₁₋₆, alkyl)₂, —N(C₁₋₆ alkyl)₂,—N(C₁₋₆ alkyl)₃ ⁺X⁻, —NH(C₁₋₆ alkyl)₂ ⁺X⁻, —NH₂(C₁₋₆ alkyl)⁺X⁻, —NH₃⁺X⁻, —N(OC₁₋₄alkyl)(C₁₋₆alkyl), —N(OH)(C₁₋₆ alkyl), —NH(OH), —SH,—SC₁₋₆alkyl, —SS(C₁₋₆, alkyl), —C(═O)(C₁₋₆, alkyl), —CO₂H, —CO₂(C₁₋₆alkyl), —OC(═O)(C₁₋₆ alkyl), —OCO₂(C₄ alkyl), —C(═O)NH₂, —C(═O)N(C₁₋₆alkyl)₂, —OC(═O)NH(C₁₋₆alkyl), —NHC(═O)(C₁₋₄ alkyl), —N(C₁₋₆alkyl)C(═O)(C₁₋₆ alkyl), —NHCO₂(C₁₋₆alkyl), —NHC(═O)N(C₁₋₆ alkyl)₂,—NHC(═O)NH(C₁₋₆ alkyl), —NHC(═O)NH₂, —C(═NH)O(C₁₋₆ alkyl), —OC(═NH)(C₁₋₆alkyl), —OC(═NH)OC₁₋₆alkyl, —C(═NH)N(C₁₋₆alkyl)₂, —C(═NH)NH(C₁₋₆ alkyl),—C(═NH)NH₂, —OC(═NH)N(C₁₋₆ alkyl)₂, —OC(NH)NH(C₁₋₆ alkyl), —OC(NH)NH₂,—NHC(NH)N(C₁₋₆alkyl)₂, —NHC(═NH)NH₂, —NHSO₂(C₁₋₆ alkyl), —SO₂N(C₁₋₆alkyl)₂, —SO₂NH(C₁₋₆ alkyl), —SO₂NH₂, —SO₂C₁₋₆ alkyl, —S₂OC₁₋₆ alkyl,—OSO₂C₁₋₆alkyl, —SOC₁₋₆ alkyl, —Si(C₁₋₆ alkyl)₃, —OSi(C₁₋₄alkyl)₃-C(═S)N(C₄ alkyl)₂, C(═S)NH(C₁₋₆ alkyl), C(═S)NH₂, —C(═O)S(C₁₋₆alkyl), —C(═S)SC₁₋₆ alkyl, —SC(═S)SC₁₋₆ alkyl, —P(═O)(OC₁₋₆ alkyl)₂,—P(═O)(C₁₋₆ alkyl)₂, —OP(═O)(C₁₋₆ alkyl)₂, —OP(═O)(OC₁₋₆ alkyl)₂, C₁₋₆alkyl, C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, heteroC₁₋₆alkyl,heteroC₂₋₆alkenyl, heteroC₂₋₆alkynyl, C₃₋₁₀ carbocyclyl, C₆₋₁₀ to aryl,3-10 membered heterocyclyl, 5-10 membered heteroaryl; or two geminalR^(gg) substituents can be joined to form ═O or ═S; wherein X is acounterion.

In certain embodiments, the carbon atom substituents are independentlyhalogen, substituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, —OR^(aa), —SR^(aa), —N(R^(bb))₂, —CN, —SCN,—NO₂, —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, —OC(═O)R^(aa),—OCO₂R^(aa), —OC(═O)N(R^(bb))₂, —NR^(bb)C(═O)R^(aa), —NR^(bb)CO₂R^(aa),or —NR^(bb)C(═O)N(R^(bb))₂. In certain embodiments, the carbon atomsubstituents are independently halogen, substituted (e.g., substitutedwith one or more halogen) or unsubstituted C₁₋₆ alkyl, —OR^(aa), —SR,—N(R^(aa))₂, —CN, —SCN, —NO₂, —C(═O)R^(aa), —CO₂R^(aa),—C(═O)N(R^(bb))₂, —OC(═O)R^(aa), —OCO₂R^(aa), —OC(═O)N(R^(bb))₂,—NR^(bb)C(═O)R^(aa), —NR^(bb)CO₂R^(aa), or —NR^(bb)C(═O)N(R^(bb))₂,wherein R^(aa) is hydrogen, substituted (e.g., substituted with one ormore halogen) or unsubstituted C₁₋₆ alkyl, an oxygen protecting groupwhen attached to an oxygen atom, or a sulfur protecting group (e.g.,acetamidomethyl, t-Bu, 3-nitro-2-pyridine sulfenyl, 2-pyridine-sulfenyl,or triphenylmethyl) when attached to a sulfur atom; and each R^(bb) isindependently hydrogen, substituted (e.g., substituted with one or morehalogen) or unsubstituted C₁₋₆ alkyl, or a nitrogen protecting group. Incertain embodiments, the carbon atom substituents are independentlyhalogen, substituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, —OR^(aa), —SR, —N(R^(bb))₂, —CN, —SCN, or—NO₂. In certain embodiments, the carbon atom substituents areindependently halogen, substituted (e.g., substituted with one or morehalogen moieties) or unsubstituted C₁₋₆ alkyl, —OR^(aa), —SR^(aa),—N(R^(bb))₂, —CN, —SCN, or —NO₂, wherein R^(aa) is hydrogen, substituted(e.g., substituted with one or more halogen) or unsubstituted C₁₋₆alkyl, an oxygen protecting group when attached to an oxygen atom, or asulfur protecting group (e.g., acetamidomethyl, t-Bu, 3-nitro-2-pyridinesulfenyl, 2-pyridine-sulfenyl, or triphenylmethyl) when attached to asulfur atom; and each R^(bb) is independently hydrogen, substituted(e.g., substituted with one or more halogen) or unsubstituted C₁₋₆alkyl, or a nitrogen protecting group.

A “counterion” or “anionic counterion” is a negatively charged groupassociated with a positively charged group in order to maintainelectronic neutrality. An anionic counterion may be monovalent (i.e.,including one formal negative charge). An anionic counterion may also bemultivalent (i.e., including more than one formal negative charge), suchas divalent or trivalent. Exemplary counterions include halide ions(e.g, F⁻, C⁻, Br⁻, I⁻), NO₃ ⁻, ClO₄ ⁻, OH⁻, H₂PO₄ ⁻, HCO₃ ⁻, HSO₄ ⁻,sulfonate ions (e.g., methansulfonate, trifluoromethanesulfonate,p-toluenesulfonate, benzenesulfonate, 10-camphor sulfonate,naphthalene-2-sulfonate, naphthalene-1-sulfonic acid-5-sulfonate,ethan-1-sulfonic acid-2-sulfonate, and the like), carboxylate ions(e.g., acetate, propanoate, benzoate, glycerate, lactate, tartrate,glycolate, gluconate, and the like), BF₄ ⁻, PF₄ ⁻, PF₆ ⁻, AsF₆ ⁻, SbF₆⁻, B[3,5-(CF₃)₂C₆H₃]₄]⁻, B(C₆F₅)₄ ⁻, BPh₄ ⁻, Al(OC(CF₃)₃)₄ ⁻, andcarborane anions (e.g., CB₁₁H₁₂ ⁻ or (HCB₁₁Me₅Br₆)⁻). Exemplarycounterions which may be multivalent include CO₃ ²⁻, HPO₄ ²⁻, PO₄ ³⁻,B₄O₇ ²⁻, SO₄ ²⁻, S₂O₃ ²⁻, carboxylate anions (e.g., tartrate, citrate,fumarate, maleate, malate, malonate, gluconate, succinate, glutarate,adipate, pimelate, suberate, azelate, sebacate, salicylate, phthalates,aspartate, glutamate, and the like), and carboranes.

“Halo” or “halogen” refers to fluorine (fluoro, —F), chlorine (chloro,—Cl), bromine (bromo, —Br), or iodine (iodo, —I).

Nitrogen atoms can be substituted or unsubstituted as valency permits,and include primary, secondary, tertiary, and quaternary nitrogen atoms.Exemplary nitrogen atom substituents include hydrogen, —OH, —OR^(aa),—N(R^(cc))₂, —CN, —C(═O)R^(aa), —C(═O)N(R^(cc))₂, —CO₂R^(aa),—SO₂R^(aa), —C(═NR^(bb))R^(aa), —C(═NR^(cc))OR^(aa),—C(═NR^(cc))N(R^(cc))₂, —SO₂N(R^(cc))₂, —SO₂R^(cc), —SO₂OR^(cc),—SOR^(aa), —C(═S)N(R^(cc))₂, —C(═O)SR^(cc), —C(═S)SR^(cc),—P(═O)(OR^(cc))₂, —P(═O)(R^(aa))₂, —P(═O)(N(R^(cc))₂)₂, C₁₋₁₀ alkyl,C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, heteroC₁₋₁₀alkyl,heteroC₂₋₁₀alkenyl, heteroC₂₋₁₀alkynyl, C₃₋₁₀ carbocyclyl, 3-14 memberedheterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or two R^(cc)groups attached to an N atom are joined to form a 3-14 memberedheterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl,alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl,carbocyclyl, heterocyclyl, aryl, and heteroaryl is independentlysubstituted with 0, 1, 2, 3, 4, or 5 R^(d)d groups, and wherein R^(aa),R^(bb), R^(cc) and R^(dd) are as defined above.

In certain embodiments, the nitrogen atom substituents are independentlysubstituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, ora nitrogen protecting group. In certain embodiments, the nitrogen atomsubstituents are independently substituted (e.g., substituted with oneor more halogen) or unsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa),—C(═O)N(R^(bb))₂, or a nitrogen protecting group, wherein R^(aa) ishydrogen, substituted (e.g., substituted with one or more halogen) orunsubstituted C¹⁻⁶ alkyl, or an oxygen protecting group when attached toan oxygen atom; and each R^(bb) is independently hydrogen, substituted(e.g., substituted with one or more halogen) or unsubstituted C₁₋₆alkyl, or a nitrogen protecting group. In certain embodiments, thenitrogen atom substituents are independently substituted (e.g.,substituted with one or more halogen) or unsubstituted C₁₋₆ alkyl or anitrogen protecting group.

In certain embodiments, the substituent present on a nitrogen atom is anitrogen protecting group (also referred to as an amino protectinggroup). Nitrogen protecting groups include —OH, —OR^(aa), —N(R^(cc))₂,—C(═O)R^(aa), —C(═O)N(R^(cc))₂, —CO₂R^(aa), —SO₂R^(aa),—C(═NR^(cc))R^(aa), —C(═NR^(cc))OR^(aa), —C(═NR^(cc))N(R^(cc))₂,—SO₂N(R^(cc))₂, —S₂R^(cc), —SO₂OR^(cc), —SOR^(aa), —C(═S)N(R^(cc))₂,—C(═O)SR^(cc), —C(═S)SR^(aa), C₁₋₁₀ alkyl (e.g., aralkyl,heteroaralkyl), C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl groups,wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl,aralkyl, aryl, and heteroaryl is independently substituted with 0, 1, 2,3, 4, or 5 R^(dd) groups, and wherein R^(aa), R^(bb), R^(cc), and R_(dd)are as defined herein. Nitrogen protecting groups are well known in theart and include those described in detail in Protecting Groups inOrganic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, JohnWiley & Sons, 1999, incorporated herein by reference.

Amide nitrogen protecting groups (e.g., —C(═O)R^(aa)) include formamide,acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide,phenylacetamide, 3-phenylpropanamide, picolinamide,3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide,p-phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide,acetoacetamide, (N′-dithiobenzyloxyacylamino)acetamide,3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide,2-methyl-2-(o-nitrophenoxy)propanamide,2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide,3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethionine,onitrobenzamide, and o-(benzoyloxymethyl)benzamide.

Carbamate nitrogen protecting groups (e.g., —C(═O)OR^(aa)) includemethyl carbamate, ethyl carbamate, 9-fluorenylmethyl carbamate (Fmoc),9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethylcarbamate,2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methylcarbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc),2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate(Teoc), 2-phenylethyl carbamate (hZ), 1-(1-adamantyl)-1-methylethylcarbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate,1,1-dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC),1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC),1-methyl-(4-biphenylyl)ethyl carbamate (Bpoc),1-(3,5-di-1-butylphenyl)-1-methylethyl carbamate (l-Bumeoc), 2-(2′- and4′-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethylcarbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinylcarbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate(Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc),8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithiocarbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz),p-nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzylcarbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzylcarbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate,2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate,2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methylcarbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc),2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate(Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc),1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate,p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate,2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenylcarbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate,3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methylcarbamate, t-amyl carbamate, S-benzyl thiocarbamate, p-cyanobenzylcarbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentylcarbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate,2,2-dimethoxyacylvinyl carbamate, o-(N,N-dimethylcarboxamido)benzylcarbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate,1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate,2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborynl carbamate,isobutyl carbamate, isonicotinyl carbamate,p-(p′-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate,1-methylcyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate,1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate,1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethylcarbamate, 1-methyl-(4-pyridyl)ethyl carbamate, phenyl carbamate,p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate,4-(trimethylammonium)benzyl carbamate, and 2,4,6-trimethylbenzylcarbamate.

Sulfonamide nitrogen protecting groups (e.g., —S(═O)₂R^(aa)) includep-toluenesulfonamide (Ts), benzenesulfonamide,2,3,6,-trimethyl-4-methoxybenzenesulfonamide (Mtr),2,4,6-trimethoxybenzenesulfonamide (Mtb),2,6-dimethyl-4-methoxybenzenesulfonamide (Pme),2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte),4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide(Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds),2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide(Ms), s-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide,4-(4′,8′-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS),benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

Other nitrogen protecting groups include phenothiazinyl-(10)-acylderivative, N′-p-toluenesulfonylaminoacyl derivative,N′-phenylaminothioacyl derivative, N-benzoylphenylalanyl derivative,N-acetylmethionine derivative, 4,5-diphenyl-3-oxazolin-2-one,N-phthalimide, N-dithiasuccinimide (Dts), N-2,3-diphenylmaleimide,N-2,5-dimethylpyrrole, N-1,1,4,4-tetramethyldisilylazacyclopentaneadduct (STABASE), 5-substituted1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted3,5-dinitro-4-pyridone, N-methylamine, N-allylamine,N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine,N(1-isopropyl-4-nitro-2-oxo-3-pyrrolin-3-yl)amine, quaternary ammoniumsalts, N-benzylamine, N-di(4-methoxyphenyl)methylamine,N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr),N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr),N-9-phenylfluorenylamine (PhF),N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm),N-2-picolylamino N′-oxide, N-1,1-dimethylthiomethyleneamine,N-benzylideneamine, N p-methoxybenzylideneamine,N-diphenylmethyleneamine, N-[(2-pyridyl)mesityl]methyleneamine,N-(N′,N′-dimethylaminomethylene)amine, N′-isopropylidenediamine,N-p-nitrobenzylideneamine, N-salicylideneamine,N-5-chlorosalicylideneamine,N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine,N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine,N-borane derivative, N-diphenylborinic acid derivative,N-[phenyl(pentaacylchromium- or tungsten)acyl]amine, N-copper chelate,N-zinc chelate, N-nitroamine, N-nitrosoamine, amine Noxide,diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt),diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzylphosphoramidate, diphenyl phosphoramidate, benzenesulfenamide,o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide,pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide,triphenylmethylsulfenamide, and 3-nitropyridinesulfenamide (Npys).

In certain embodiments, a nitrogen protecting group is Bn, Boc, Cbz,Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts.

In certain embodiments, the oxygen atom substituents are independentlysubstituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, oran oxygen protecting group. In certain embodiments, the oxygen atomsubstituents are independently substituted (e.g., substituted with oneor more halogen) or unsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa),—C(═O)N(R^(bb))₂, or an oxygen protecting group, wherein R^(aa) ishydrogen, substituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, or an oxygen protecting group when attached toan oxygen atom; and each R^(bb) is independently hydrogen, substituted(e.g., substituted with one or more halogen) or unsubstituted C₁₋₆alkyl, or a nitrogen protecting group. In certain embodiments, theoxygen atom substituents are independently substituted (e.g.,substituted with one or more halogen) or unsubstituted C₁₋₆ alkyl or anoxygen protecting group.

In certain embodiments, the substituent present on an oxygen atom is anoxygen protecting group (also referred to herein as an “hydroxylprotecting group”). Oxygen protecting groups include —R^(aa),—N(R^(bb))₂, —C(═O)SR^(aa), —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂,—C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂,—S(═O)R^(aa), —SO₂R^(aa), —Si(R^(aa))₃, —P(R^(cc))₂, —P(R^(cc))₃ ⁺X⁻,—P(OR^(cc))₂, —P(OR^(cc))₃ ⁺X⁻, —P(═O)R^(aa), —P(═O)(OR^(cc))₂, and—P(═O)(N(R^(bb))₂)₂, wherein X⁻, R^(aa), R^(bb), and R^(cc) are asdefined herein. Oxygen protecting groups are well known in the art andinclude those described in detail in Protecting Groups in OrganicSynthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley &Sons, 1999, incorporated herein by reference.

Exemplary oxygen protecting groups include methyl, methoxylmethyl (MOM),methylthiomethyl (MTM), t-butylthiomethyl,(phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM),p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM),guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM),siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl,bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR),tetrahydropyranyl (THP), 3-bromotetrahydropyranyl,tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl(MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranylS,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl(CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl,2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl,l-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl,1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl,2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl,t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl,benzyl (Bn), p-methoxybenzyl, 3,4-<dimethoxybenzyl, o nitrobenzyl,p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl,p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxido,diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl,triphenylmethyl, α-naphthyldiphenylmethyl,p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl,tri(p-methoxyphenyl)methyl, 4-4′-bromophenacyloxyphenyl)diphenylmethyl,4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl,4,4′,4″-tris(levulinoyloxyphenyl)methyl,4,4′,4″-tris(benzoyloxyphenyl)methyl,3-(imidazol-1-yl)bis(4′,4″-dimethoxyphenyl)methyl,1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl,9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl,1,3-benzodisulfuran-2-yl, benzisothiazolyl S,S-dioxido, trimethylsilyl(TMS), triethylsilyl (TES), triisopropylsilyl (TIPS),dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS),dimethylthexylsilyl, 1-butyldimethylsilyl (TBDMS), i-butyldiphenylsilyl(TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl,diphenylmethylsilyl (DPMS), 1-butylmethoxyphenylsilyl (TBMPS), formate,benzoylformate, acetate, chloroacetate, dichloroacetate,trichloroacetate, trifluoroacetate, methoxyacetate,triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate,3-phenylpropionate, 4-oxopentanoate (levulinate),4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate,adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate,2,4,6-trimethylbenzoate (mesitoate), alkyl methyl carbonate,9-fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate(TMSEC), 2-(phenylsulfonyl) ethyl carbonate (Psec),2-(triphenylphosphonio) ethyl carbonate (Peoc), alkyl isobutylcarbonate, alkyl vinyl carbonate alkyl allyl carbonate, alkylp-nitrophenyl carbonate, alkyl benzyl carbonate, alkyl p-methoxybenzylcarbonate, alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzylcarbonate, alkyl p-nitrobenzyl carbonate, alkyl S-benzyl thiocarbonate,4-ethoxy-1-naphthyl carbonate, methyl dithiocarbonate, 2-iodobenzoate,4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate,2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl,4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate,2,6-dichloro-4-methylphenoxyacetate,2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate,2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate,isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate,o-(methoxyacyl)benzoate, α-naphthoate, nitrate, alkylN,N,N′,N′-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate,borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate,sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate(Ts).

In certain embodiments, an oxygen protecting group is silyl, TBDPS,TBDMS, TIPS, TES, TMS, MOM, THP, t-Bu, Bn, allyl, acetyl, pivaloyl, orbenzoyl.

In certain embodiments, the sulfur atom substituents are independentlysubstituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, ora sulfur protecting group. In certain embodiments, the sulfur atomsubstituents are independently substituted (e.g, substituted with one ormore halogen) or unsubstituted C₁₋₆ alkyl, —C(═O)R^(aa), —CO₂R^(aa),—C(═O)N(R^(bb))₂, or a sulfur protecting group, wherein R^(aa) ishydrogen, substituted (e.g., substituted with one or more halogen) orunsubstituted C₁₋₆ alkyl, or an oxygen protecting group when attached toan oxygen atom; and each R^(bb) is independently hydrogen, substituted(e.g., substituted with one or more halogen) or unsubstituted C₁₋₆alkyl, or a nitrogen protecting group. In certain embodiments, thesulfur atom substituents are independently substituted (e.g.,substituted with one or more halogen) or unsubstituted C₁₋₆ alkyl or asulfur protecting group.

In certain embodiments, the substituent present on a sulfur atom is asulfur protecting group (also referred to as a “thiol protectinggroup”). Sulfur protecting groups include —R^(aa), —N(R^(bb))₂,—C(═O)SR^(aa), —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂,—C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂,—S(═O)R^(aa), —SO₂R^(aa), —Si(R^(aa))₃, —P(R^(cc))₂, —P(R^(cc))₃ ⁺X⁻,—P(OR^(cc))₂, —P(OR^(cc))₃ ⁺X⁻, —P(═O)(R^(aa))₂, —P(═O)(OR^(cc))₂, and—P(═O)(N(R^(bb))₂)₂, wherein R^(aa), R^(bb), and R^(cc) are as definedherein. Sulfur protecting groups are well known in the art and includethose described in detail in Protecting Groups in Organic Synthesis, T.W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999,incorporated herein by reference. In certain embodiments, a sulfurprotecting group is acetamidomethyl, t-Bu, 3-nitro-2-pyridine sulfenyl,2-pyridine-sulfenyl, or triphenylmethyl.

The “molecular weight” of —R, wherein —R is any monovalent moiety, iscalculated by subtracting the atomic weight of a hydrogen atom from themolecular weight of the molecule R—H. The “molecular weight” of -L-,wherein -L- is any divalent moiety, is calculated by subtracting thecombined atomic weight of two hydrogen atoms from the molecular weightof the molecule H-L-H.

In certain embodiments, the molecular weight of a substituent is lowerthan 200, lower than 150, lower than 100, lower than 50, or lower than25 g/mol. In certain embodiments, a substituent consists of carbon,hydrogen, fluorine, chlorine, bromine, iodine, oxygen, sulfur, nitrogen,and/or silicon atoms. In certain embodiments, a substituent consists ofcarbon, hydrogen, fluorine, chlorine, bromine, and/or iodine atoms. Incertain embodiments, a substituent consists of carbon, hydrogen, and/orfluorine atoms. In certain embodiments, a substituent does not compriseone or more, two or more, or three or more hydrogen bond donors. Incertain embodiments, a substituent does not comprise one or more, two ormore, or three or more hydrogen bond acceptors.

The term “leaving group” is given its ordinary meaning in the art ofsynthetic organic chemistry and refers to an atom or a group capable ofbeing displaced by a nucleophile.

Examples of suitable leaving groups include halogen (such as F, Cl, Br,or I (iodine)), alkoxycarbonyloxy, aryloxycarbonyloxy,alkanesulfonyloxy, arenesulfonyloxy, alkyl-carbonyloxy (e.g., acetoxy),arylcarbonyloxy, aryloxy, methoxy, NO-dimethylhydroxylamino, pixyl, andhaloformates. In some cases, the leaving group is a sulfonic acid ester,such as toluenesulfonate (tosylate, —OTs), methanesulfonate (mesylate,—OMs), p-bromobenzenesulfonyloxy (brosylate, —OBs), —OS(═O)₂(CF₂)₃CF₃(nonaflate, —ONf), or trifluoromethanesulfonate (triflate, —OTf). Insome cases, the leaving group is a brosylate, such asp-bromobenzenesulfonyloxy. In some cases, the leaving group is anosylate, such as 2-nitrobenzenesulfonyloxy. In some embodiments, theleaving group is a sulfonate-containing group. In some embodiments, theleaving group is a tosylate group. The leaving group may also be aphosphineoxide (e.g., formed during a Mitsunobu reaction) or an internalleaving group such as an epoxide or cyclic sulfate. Other examples ofleaving groups are water, ammonia, alcohols, ether moieties, thioethermoieties, zinc halides, magnesium moieties, diazonium salts, and coppermoieties.

The term “salt” refers to ionic compounds that result from theneutralization reaction of an acid and a base. A salt is composed of oneor more cations (positively charged ions) and one or more anions(negative ions) so that the salt is electrically neutral (without a netcharge). Salts of the compounds of this disclosure include those derivedfrom inorganic and organic acids and bases. Examples of acid additionsalts are salts of an amino group formed with inorganic acids such ashydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, andperchloric acid, or with organic acids such as acetic acid, oxalic acid,maleic acid, tartaric acid, citric acid, succinic acid, or malonic acidor by using other methods known in the art such as ion exchange. Othersalts include adipate, alginate, ascorbate, aspartate, benzenesulfonate,benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate,citrate, cyclopentanepropionate, digluconate, dodecylsulfate,ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate,gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide,2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, laurylsulfate, malate, maleate, malonate, methanesulfonate,2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate,pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate,pivalate, propionate, stearate, succinate, sulfate, tartrate,thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and thelike. Salts derived from appropriate bases include alkali metal,alkaline earth metal, ammonium and N⁺(C₁₋₄ alkyl)₄ salts. Representativealkali or alkaline earth metal salts include sodium, lithium, potassium,calcium, magnesium, and the like. Further salts include ammonium,quaternary ammonium, and amine cations formed using counterions such ashalide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkylsulfonate, and aryl sulfonate. “Compounds” include, e.g., smallmolecules and macromolecules. Macromolecules include, e.g., polymers,peptides, proteins, carbohydrates, monosaccharides, oligosaccharides,polysaccharides, nucleoproteins, mucoproteins, lipoproteins, syntheticpolypeptides or proteins, glycoproteins, steroids, nucleic acids, DNAs,RNAs, nucleotides, nucleosides, oligonucleotides, antisenseoligonucleotides, lipids, hormones, vitamins, and cells.

The term “small molecule” refers to molecules, whethernaturally-occurring or artificially created (e.g., via chemicalsynthesis) that have a relatively low molecular weight. Typically, asmall molecule is an organic compound (i.e., it contains carbon). Thesmall molecule may contain multiple carbon-carbon bonds, stereocenters,and other functional groups (e.g., amines, hydroxyl, carbonyls, andheterocyclic rings, etc.). In certain embodiments, the molecular weightof a small molecule is not more than 2,000 g/mol. In certainembodiments, the molecular weight of a small molecule is not more than1,500 g/mol. In certain embodiments, the molecular weight of a smallmolecule is not more than 1,000 g/mol, not more than 900 g/mol, not morethan 800 g/mol, not more than 700 g/mol, not more than 600 g/mol, notmore than 500 g/mol, not more than 400 g/mol, not more than 300 g/mol,not more than 200 g/mol, or not more than 100 g/mol. In certainembodiments, the molecular weight of a small molecule is at least 100g/mol, at least 200 g/mol, at least 300 g/mol, at least 400 g/mol, atleast 500 g/mol, at least 600 g/mol, at least 700 g/mol, at least 800g/mol, or at least 900 g/mol, or at least 1,000 g/mol. Combinations ofthe above ranges (e.g., at least 200 g/mol and not more than 500 g/mol)are also possible. In certain embodiments, the small molecule is atherapeutically active agent such as a drug (e.g., a molecule approvedby the U.S. Food and Drug Administration as provided in the Code ofFederal Regulations (C.F.R.)). The small molecule may also be complexedwith one or more metal atoms and/or metal ions. In this instance, thesmall molecule is also referred to as a “small organometallic molecule.”Preferred small molecules are biologically active in that they produce abiological effect in animals, preferably mammals, more preferablyhumans. Small molecules include radionuclides and imaging agents. Incertain embodiments, the small molecule is a drug. Preferably, thoughnot necessarily, the drug is one that has already been deemed safe andeffective for use in humans or animals by the appropriate governmentalagency or regulatory body. For example, drugs approved for human use arelisted by the FDA under 21 C.F.R. §§ 330.5, 331 through 361, and 440through 460, incorporated herein by reference; drugs for veterinary useare listed by the FDA under 21 C.F.R. §§ 500 through 589, incorporatedherein by reference. All listed drugs are considered acceptable for usein accordance with the present disclosure.

The term “oligomer” refers to a compound comprising two to ten,inclusive, covalently connected repeating units. In certain embodiments,an oligomer comprises two to five, inclusive, covalently connectedrepeating units. In certain embodiments, an oligomer comprises six toten, inclusive, covalently connected repeating units.

The term “polymer” refers to a compound comprising eleven or morecovalently connected repeating units. In certain embodiments, a polymeris naturally occurring. In certain embodiments, a polymer is synthetic(e.g., not naturally occurring). In certain embodiments, the M_(W) of apolymer is between 1,000 and 2,000, between 2,000 and 10,000, between10,000 and 30,000, between 30,000 and 100,000, between 100,000 and300,000, between 300,000 and 1,000,000, g/mol, inclusive. In certainembodiments, the M_(W) of a polymer is between 2,000 and 1,000,000,g/mol, inclusive.

The term “average molecular weight” may encompass the number averagemolecular weight (M_(n)), weight average molecular weight (M_(w)),higher average molecular weight (M_(z) or M_(z)+1), GPC/SEC (gelpermeation chromatography/size-exclusion chromatography)-determinedaverage molecular weight (M_(p)), and viscosity average molecular weight(M_(v)). Average molecular weight may also refer to average molecularweight as determined by gel permeation chromatography.

The term “degree of polymerization” (DP) refers to the number ofrepeating units in a polymer. In certain embodiments, the DP isdetermined by a chromatographic method, such as gel permeationchromatography. For a homopolymer, the DP refers to the number ofrepeating units included in the homopolymer. For a copolymer of twotypes of monomers (e.g., a first monomer and a second monomer) whereinthe molar ratio of the two types of monomers is about 1:1, the DP refersto the number of repeating units of either one of the two type ofmonomers included in the copolymer. For a copolymer of two types ofmonomers (e.g., a first monomer and a second monomer) wherein the molarratio of the two types of monomers is not about 1:1, two DPs may beused. A first DP refers to the number of repeating units of the firstmonomer included in the copolymer, and a second DP refers to the numberof repeating units of the second monomer included in the copolymer.Unless provided otherwise, a DP of “xx”, wherein xx is an integer,refers to the number of repeating units of either one of the two typesof monomers of a copolymer of two types of monomers (e.g., a firstmonomer and a second monomer) wherein the molar ratio of the two typesof monomers is about 1:1. Unless provided otherwise, a DP of “xx-yy”,wherein xx and yy are integers, refers to xx being the number ofrepeating units of the first monomer, and yy being the number ofrepeating units of the second monomer, of a copolymer of two types ofmonomers (e.g., a first monomer and a second monomer) wherein the molarratio of the two types of monomers is not about 1:1.

The term “ring-opening metathesis polymerization (ROMP)” refers to atype of olefin metathesis chain-growth polymerization that is driven bythe relief of ring strain in cyclic olefins (e.g. norbornene orcyclopentene). The catalysts used in the ROMP reaction (“metathesiscatalyst”) include RuCl₃/alcohol mixture,bis(cyclopentadienyl)dimethylzirconium(IV),dichloro[1,3-bis(2,6-isopropylphenyl)-2-imidazolidinylidene](benzylidene)(tricyclohexylphosphine)ruthenium(II),dichloro[1,3-Bis(2-methylphenyl)-2-imidazolidinylidene](benzylidene)(tricyclohexylphosphine)ruthenium(II),dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene][3-(2-pyridinyl)propylidene]ruthenium(II),dichloro(3-methyl-2-butenylidene)bis(tricyclopentylphosphine)ruthenium(II),dichloro[1,3-bis(2-methylphenyl)-2-imidazolidinylidene](2-isopropoxyphenylmethylene)ruthenium(II)(Grubbs C571),dichloro(benzylidene)bis(tricyclohexylphosphine)ruthenium(II) (GrubbsI),dichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)(tricyclohexylphosphine)ruthenium(II) (Grubbs II), anddichloro[1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene](benzylidene)bis(3-bromopyridine)ruthenium(II)(Grubbs III).

The term “v/v” refers to volume per volume and is used herein to expressconcentrations of monomers. Unless otherwise provided, a percentconcentration of a second monomer in a first monomer is expressed inv/v. For example, a mixture of a first monomer and 10% second monomerrefers to a mixture of a first monomer and a second monomer, wherein thevolume of the second monomer is 10% of the combined volumes of the firstand second monomers.

The disclosure is not intended to be limited in any manner by the aboveexemplary listing of substituents. Additional terms may be defined inother sections of this disclosure.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

There is a need to improve the reprocessability of thermosets. Anapproach to convert existing thermosets into degradable variants wouldinvolve the use of a low-cost co-monomer additive that, when introducedat low levels during standard thermoset formulation conditions, couldintroduce cleavable bonds at precise locations within the thermosetpolymer network enabling material degradation with otherwise little tono impact on properties. The use of such co-monomer strategies to imbuecommodity polymers with degradability or reprocessability is exceedinglyrare (6, 7). To our knowledge, such an approach has not beendemonstrated in the context of existing high-performance thermosets(8-10).

Here, in one aspect, we establish this co-monomer approach in thecontext of commercially important thermosets, such aspoly-dicyclopentadiene (pDCPD). pDCPD may be prepared throughring-opening metathesis polymerization (ROMP) of the abundanthydrocarbon feedstock dicyclopentadiene (DCPD). See, e.g., U.S. patentapplication Ser. No. 16/542,824, filed Aug. 16, 2019, which isincorporated herein by reference. In this curing process, the norbornenecomponent of DCPD polymerizes rapidly to produce linear polymer strandsthat are subsequently crosslinked through metathesis reactions of theircyclopentene sidechains. The resulting entirely hydrocarbon thermoset isvalued for its high impact resistance and compatibility with reactioninjection molding processes (11-18). Moreover, emerging manufacturingconcepts, such as frontal polymerization, enable pDCPD curing withenergy consumption orders-of-magnitude lower than other thermosets(e.g., epoxies) (15, 16).

We show that by incorporation of a cyclic silyl ether

into the existing pDCPD manufacturing workflow, it is possible toprepare pDCPD derivatives with properties that are nearlyindistinguishable from native pDCPD, but with the capability to bereadily degraded into soluble, hydroxylated hydrocarbon fragments thatare functional scaffolds for upcycling. Moreover, solution-state NMRstudies of these soluble products provide unprecedent insight into thestructure of pDCPD. Remarkably, when materials prepared using aco-monomer approach, which feature degradable linkages within theirpolynorbornene strands, were compared to analogous pDCPD derivativeswith cleavable crosslinks, we found that only the former materials fullydegrade into soluble species at low co-monomer incorporation. Thisobservation is rationalized by natural topological differences betweenstrands and crosslinks in pDCPD that are shared across many types ofpolymer networks, establishing a key design principle—cleavable bondlocation—that may augment the development of degradable thermosets.

Functional Oligomers, Functional Polymers, Hydroxylated Polymers,Compounds, Coploymers, and Methods of Preparation, Compositions, andKits Thereof

In one aspect, the present disclosure describes functional oligomer orfunctional polymer comprising:

i) one or more instances of linear units, wherein each instance of thelinear units is of the formula:

ii) one or more instances of functional units, wherein each instance ofthe functional units is independently of the formula:

iii) optionally one or more instances of crosslinking units, whereineach instance of the crosslinking units is of the formula:

and

iv) optionally one or more additional linear units, one or moreadditional terminal units, and/or one or more additional crosslinkingunits;

wherein:

each instance of Z is independently a single bond, C(R^(P))₂, or O;

each instance of R^(P) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl;

each instance of

is independently a single or double bond;

each instance of R^(H) is independently hydrogen, halogen, substitutedor unsubstituted alkyl, substituted or unsubstituted alkenyl,substituted or unsubstituted alkynyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, —OR, —OCN,—OC(═O)R^(a), —OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂,—OS(═O)R^(a), —OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a),—OS(═O)₂OR^(a), —OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)),OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo, —N(R^(a))₂, —N═C(R^(a))₂,═NR^(a), —NC, —NCO, —N₃, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a),—NR^(a)C(═O)N(R^(a))₂, —NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR^(a),—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),—NR^(a)S(═O)₂N(R^(a))₂, —SR, —SCN, —S(═O)R^(a), —S(═O)OR,—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O₂OR^(a), —S(═O)₂N(R^(a))₂, —SeR^(a),halogen, —CN, —C(═NR^(a))R^(a), —C(═NR^(a))OR^(a), —C(═NR^(a))N(R^(a)),—C(═O)R^(a), —C(═O)OR^(a), —C(═O)SR^(a), —C(═S)OR, or —C(═O)N(R^(a))₂;

or the two instances of R^(H) of one or more instances of

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring;

each instance of R^(a) is independently hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted alkenyl, substitutedor unsubstituted alkynyl, substituted or unsubstituted, monocycliccarbocyclyl, substituted or unsubstituted, monocyclic heterocyclyl,substituted or unsubstituted, monocyclic aryl, substituted orunsubstituted, monocyclic heteroaryl, a nitrogen protecting group whenattached to a nitrogen atom, an oxygen protecting group when attached toan oxygen atom, or a sulfur protecting group when attached to a sulfuratom, or two instances of R^(a) are joined to form substituted orunsubstituted heterocyclyl or substituted or unsubstituted heteroaryl;

each instance of R^(J) is independently —OR, —OCN, —OC(═O)R^(a),—OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂, —OS(═O)R^(a),—OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a), —OS(═O)₂OR^(a),—OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)),—OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo, —N(R^(a))₂, —N═C(R^(a))₂, ═NR,—NC, —NCO, —N₃, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a),—NR^(a)C(═O)N(R^(a))₂, —NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR,—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),—NR^(a)S(═O)₂N(R^(a))₂, —SR, —SCN, —S(═O)R^(a), —S(═O)OR^(a),—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂,—SeR^(a), halogen, —CN, —C(═NR^(a))R^(a), —C(═Na)OR^(a),—C(═NR^(a))N(R^(a))₂, —C(═O)R^(a), —C(═O)OR^(a), —C(═O)SR^(a), —C(═S)OR,or —C(═O)N(R^(a))₂;

each instance of R^(S) is independently hydrogen or —OR^(a);

each instance of w is independently 0, 1, 2, 3, or 4;

each instance of h is independently 0, 1, 2, or 3;

each instance of i is independently 0, 1, 2, or 3;

each instance of R^(U) is independently hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted alkenyl, substitutedor unsubstituted alkynyl, substituted or unsubstitutedcarbocyclyl,substituted or unsubstitutedheterocyclyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, —OR^(a), —OCN,—OC(═O)R^(a), —OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂,OS(═O)R^(a),—OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a), —OS(═O)₂OR^(a),—OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)),—OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo, —N(R^(a))₂, —N═C(R^(a))₂, ═NR,—NC, —NCO, —N, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR,—NR^(a)C(═O)N(R^(a))₂, —NRS(═O)R^(a), —NR^(a)S(═O)OR,—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),—NR^(a)S(═O)₂N(R^(a))₂, —SR, —SCN, —S(═O)R^(a), —S(═O)OR^(a),—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂,—SeR^(a), halogen, —CN, —C(═NR³)R^(a), —C(═NR^(a))OR^(a),—C(═NR^(a))N(R^(a))₂, —C(═O)R^(a), —C(═O)OR, —C(═O)SR^(a), —C(═S)OR^(a),or —C(═O)N(R^(a))₂; and

each instance of R^(T) is independently hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted alkenyl, substitutedor unsubstituted alkynyl, substituted or unsubstituted carbocyclyl,substituted or unsubstituted heterocyclyl, substituted or unsubstitutedaryl, or substituted or unsubstituted heteroaryl.

In certain embodiments, the functional polymer is a hydroxylatedpolymer. In one aspect, the present disclosure describes hydroxylatedpolymers prepared by hydrolyzing a copolymer prepared by a methodcomprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is independently of the formula:

or salt thereof, wherein:

-   -   each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring;

-   -   each instance of Z is independently C(R^(P))₂ or O;    -   each instance of R^(P) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆alkyl; and    -   each instance of        is independently a single bond or double bond; and

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of Formula (B):

or a salt thereof; wherein:

-   -   each instance of Y is independently O or C(R^(Q))₂;    -   each instance of R^(Q) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆alkyl;    -   each instance of R^(K) is independently hydrogen, halogen,        substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or        unsubstituted carbocyclyl, substituted or unsubstituted        heterocyclyl, substituted or unsubstituted aryl, substituted or        unsubstituted heteroaryl, or —OR^(N);    -   each instance of R^(N) is independently hydrogen, substituted or        unsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,        substituted or unsubstituted carbocyclyl, substituted or        unsubstituted heterocyclyl, substituted or unsubstituted aryl,        substituted or unsubstituted heteroaryl, or an oxygen protecting        group;    -   each instance of j is independently 1, 2, or 3; and    -   each instance of k is independently 0, 1, 2, or 3;

wherein any two instances of the first monomer are the same as ordifferent from each other, and any two instances of the second monomerare the same as or different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

In certain embodiments, the functional oligomer or functional isprepared by a method comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; wherein:

Y is O or C(R^(Q))₂;

each instance of R^(Q) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl;

each instance of R^(K) is independently hydrogen, halogen, substitutedor unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstituted carbocyclyl,substituted or unsubstituted heterocyclyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, or —OR^(N);

each instance of R^(N) is independently hydrogen, substituted orunsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,substituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, substituted orunsubstituted heteroaryl, or an oxygen protecting group;

j is 1, 2, or 3; and

k is 0, 1, 2, or 3, and

iii) optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

In certain embodiments, the functional oligomer or functional polymer isprepared by a method comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof, and

iii) optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of

of the copolymer to form

In another aspect, the present disclosure describes methods of preparinga hydroxylated polymer comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is independently of the formula:

or salt thereof, wherein:

-   -   each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring;

-   -   each instance of Z is independently C(R^(P))₂ or O;    -   each instance of R^(P) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆alkyl; and    -   each instance of        is independently a single bond or double bond; and

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of Formula (B):

or a salt thereof; wherein:

-   -   each instance of Y is independently O or C(R^(Q))₂;    -   each instance of R^(Q) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆ alkyl;    -   each instance of R^(K) is independently hydrogen, halogen,        substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or        unsubstituted carbocyclyl, substituted or unsubstituted        heterocyclyl, substituted or unsubstituted aryl, substituted or        unsubstituted heteroaryl, or —OR^(N).    -   each instance of R^(N) is independently hydrogen, substituted or        unsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,        substituted or unsubstituted carbocyclyl, substituted or        unsubstituted heterocyclyl, substituted or unsubstituted aryl,        substituted or unsubstituted heteroaryl, or an oxygen protecting        group;    -   each instance of j is independently 1, 2, or 3; and    -   each instance of k is independently 0, 1, 2, or 3;

wherein any two instances of the first monomer are the same as ordifferent from each other, and any two instances of the second monomerare the same as or different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

In another aspect, the present disclosure describes methods of preparinga functional oligomer or functional polymer comprising hydrolyzing acopolymer prepared by a method comprising polymerizing in the presenceof a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; and

iii) optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

In another aspect, the present disclosure describes methods of preparinga functional oligomer or functional polymer comprising hydrolyzing acopolymer prepared by a method comprising polymerizing in the presenceof a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof;

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of the formula:

or a salt thereof; and

iii) optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of

of the copolymer to form

In another aspect, the present disclosure describes compounds of Formula(B1):

and salts thereof; wherein:

Y is O or C(R^(Q))₂;

each instance of R^(Q) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl;

each instance of R^(K) is independently hydrogen, halogen, substitutedor unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstituted carbocyclyl,substituted or unsubstituted heterocyclyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, or —OR^(N);

each instance of R^(N) is independently hydrogen, substituted orunsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,substituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, substituted orunsubstituted heteroaryl, or an oxygen protecting group;

j is 1, 2, or 3; and

k is 0, 1, 2, or 3;

provided that the compound is not of the formula:

In certain embodiments, the compound is of the formula:

or a salt thereof.

In certain embodiments, the compound is of the formula:

or a salt thereof.

In certain embodiments, the compound is of the formula:

or a salt thereof.

In certain embodiments, the compound is of the formula:

In another aspect, the present disclosure describes copolymers preparedby a method comprising polymerizing:

one or more instances of a first monomer;

one or more instances of a second monomer, wherein the second monomer isa compound of Formula (B1), or a salt thereof; and

optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other;

in the presence of a metathesis catalyst.

In another aspect, the present disclosure describes methods of preparinga copolymer comprising polymerizing:

one or more instances of a first monomer;

one or more instances of a second monomer, wherein the second monomer isa compound of Formula (B1), or a salt thereof; and

optionally one or more instances of a third monomer;

wherein any two instances of the first monomer are the same as ordifferent from each other, any two instances of the second monomer arethe same as or different from each other, any two instances of the thirdmonomer are the same as or different from each other, and each instanceof the first monomer, the second monomer, and the third monomer ifpresent, is different from each other;

in the presence of a metathesis catalyst.

In certain embodiments, the method of preparing the copolymer furthercomprises (b) exposing the copolymer to a solvent.

In certain embodiments, the method of preparing the copolymer furthercomprises (c) solid-liquid phase separation. In certain embodiments,Step (c) is subsequent to Step (b).

In certain embodiments, the method of preparing the copolymer furthercomprises curing. In some embodiments, curing forms a resin. In certainembodiments, curing is carried out at 70 to 150° C., inclusive. Incertain embodiments, curing is carried out at 100 to 150° C., inclusive.In certain embodiments, curing is carried out at 100 to 130° C.,inclusive. In certain embodiments, curing is carried out at 110 to 120°C., inclusive. In some embodiments, curing is carried out at about 110°C. In some embodiments, curing is carried out at about 120° C. In someembodiments, curing is carried out for 1 minute to 3 hours, inclusive.In some embodiments, curing is carried out for 15 minutes to 1 hour,inclusive. In some embodiments, curing is carried out for 15 minutes. Incertain embodiments, curing is carried out for 30 minutes. In someembodiments, curing is carried out for 1 hour. In certain embodiments,curing is carried out at ambient pressure. In some embodiments, curingis carried out at lower-than-ambient pressure. In some embodiments,curing is carried out at higher-than-ambient pressure.

The preparation of the copolymers may involve a metathesis reaction. Incertain embodiments, the metathesis reaction is a ring-openingmetathesis copolymerization (ROMP) (see, e.g., Liu el al. J. Am. Chem.Soc. 2012, 134, 16337; Liu, J.; Gao, A. X.; Johnson, J. A. J Vis Exp2013, e50874).

In certain embodiments, the metathesis catalyst (e.g., ROMP catalyst) isa tungsten (W), molybdenum (Mo), or ruthenium (Ru), metathesis catalyst.In certain embodiments, the metathesis catalyst is a rutheniummetathesis catalyst. Metathesis catalysts useful in the syntheticmethods described herein include catalysts as depicted below, and asdescribed in Grubbs et al., Acc. Chem. Res. 1995, 28, 446-452; U.S. Pat.No. 5,811,515; Schrock et al., Organometallics (1982) 1 1645; Gallivanet al., Tetrahedron Letters (2005) 46:2577-2580; Furstner et al., Am.Chem. Soc. (1999) 121:9453; and Chem. Eur. J. (2001) 7:5299; the entirecontents of each of which are incorporated herein by reference.

In certain embodiments, the metathesis catalyst is a Grubbs catalyst. Incertain embodiments, the Grubbs catalyst is selected from the groupconsisting of:

Benzylidenebis-(tricyclohexylphosphine)-dichlororuthenium (X═Cl);Benzylidenebis-(tricyclohexylphosphine)-dibromoruthenium (X═Br);Benzylidenebis-(tricyclohexylphosphine)-diiodoruthenium (X═I);

1,3-(Bis(mesityl)-2-imidazolidinylidene)dichloro-(phenylmethylene)(tricyclohexyl-phosphine)ruthenium (X═Cl; R=cyclohexyl);1,3-(Bis(mesityl)-2-imidazolidinylidene)dibromo-(phenylmethylene)(tricyclohexyl-phosphine)ruthenium (X═Br; R=cyclohexyl);1,3-(Bis(mesityl)-2-imidazolidinylidene)diiodo-(phenylmethylene)(tricyclohexyl-phosphine)ruthenium (X═I; R=cyclohexyl);1,3-Bis(mesityl)-2-imidazolidinylidene)dichloro-(phenylmethylene)(triphenylphosphine)ruthenium (X═Cl; R=phenyl);1,3-(Bis(mesityl)-2-imidazolidinylidene)dichloro-(phenylmethylene)(tribenzylphosphine)ruthenium (X═Cl; R=benzyl);

In certain embodiments, the metathesis catalyst is a Grubbs-Hoveydacatalyst. In certain embodiments, the Grubbs-Hoveyda catalyst isselected from the group consisting of:

In certain embodiments, the metathesis catalyst is selected from thegroup consisting of:

In certain embodiments, the metathesis catalyst is of the formula.

In certain embodiments, the metathesis catalyst is the second-generationGrubbs catalyst.

In certain embodiments, the ratio of the combined molar amounts of thefirst monomer, second monomer, and third monomer if present to the molaramount of the metathesis catalyst is not less than 2,000. In certainembodiments, the ratio of the combined molar amounts of the firstmonomer, second monomer, and third monomer if present to the molaramount of the metathesis catalyst is between 1,000 and 1,500, exclusive.In certain embodiments, the ratio of the combined molar amounts of thefirst monomer, second monomer, and third monomer if present to the molaramount of the metathesis catalyst is between 1,500 and 2,000, inclusive.In certain embodiments, the ratio of the combined molar amounts of thefirst monomer, second monomer, and third monomer if present to the molaramount of the metathesis catalyst is between 2,000 and 10,000,inclusive. In certain embodiments, the ratio of the combined molaramounts of the first monomer, second monomer, and third monomer ifpresent to the molar amount of the metathesis catalyst is between 10,000and 30,000, inclusive. In certain embodiments, the ratio of the combinedmolar amounts of the first monomer, second monomer, and third monomer ifpresent to the molar amount of the metathesis catalyst is between 30,000and 100,000, inclusive.

The ROMP can be conducted in one or more aprotic solvents. The term“aprotic solvent” means a non-nucleophilic solvent having a boilingpoint range above ambient temperature, preferably from about 25° C. toabout 190° C. at atmospheric pressure. In certain embodiments, theaprotic solvent has a boiling point from about 80° C. to about 160° C.at atmospheric pressure. In certain embodiments, the aprotic solvent hasa boiling point from about 80° C. to about 150° C. at atmosphericpressure. Examples of such solvents are methylene chloride,acetonitrile, toluene, DMF, diglyme, THF, and DMSO.

The ROMP can be quenched with a vinyl ether of the formula

Each of R^(V1), R^(V2), R^(V3), and R^(V4) is independently optionallysubstituted alkyl, optionally substituted alkenyl, optionallysubstituted alkynyl, optionally substituted carbocyclyl, optionallysubstituted phenyl, optionally substituted heterocyclyl, or optionallysubstituted heteroaryl. In certain embodiments, R^(V1) is optionallysubstituted alkyl, and R^(V2), R^(V3), and R^(V4) are hydrogen. Incertain embodiments, R^(V1) is unsubstituted alkyl, and R^(V2), R^(V3),and R^(V4) are hydrogen. In certain embodiments, R^(V1) is substitutedalkyl, and R^(V2), R^(V3), and R^(V4) are hydrogen. In certainembodiments, R^(V1) is methyl, and R^(V2), R^(V3), and R^(V4) arehydrogen. In certain embodiments, R^(V1) is ethyl, and R^(V2), R^(V3),and R^(V4) are hydrogen. In certain embodiments, R^(V1) is propyl, andR^(V2), R^(V3), and R^(V4) are hydrogen. In certain embodiments, R^(V1)is optionally substituted alkenyl, and R^(V2), R^(V3), and R^(V4) arehydrogen. In certain embodiments, R^(V1) is unsubstituted alkenyl, andR^(V2), R^(V3), and R^(V4) are hydrogen. In certain embodiments, R^(V1)is vinyl, and R^(V2), R^(V3), and R^(V4) are hydrogen. In certainembodiments, at least one of R^(V1), R^(V2), R^(V3), and R^(V4) isconjugated with a diagnostic agent as defined above. In certainembodiments, the ROMP is quenched by ethyl vinyl ether. Excess ethylvinyl ether can be removed from the copolymer under reduced pressure.

In certain embodiments, at least two instances of a variable (e.g., amoiety) are different from each other. In certain embodiments, allinstances of a variable are different from each other. In certainembodiments, all instances of a variable are the same.

In certain embodiments, at least one instance of the first monomer is ofFormula:

or salt thereof, wherein

each instance of Z is independently C(R^(P))₂ or O;

each instance of R^(P) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl;

each instance of

is independently a single bond or double bond:

each instance of R^(H) is independently hydrogen, halogen, substitutedor unsubstituted alkyl, substituted or unsubstituted alkenyl,substituted or unsubstituted alkynyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, —OR, —OCN,—OC(═O)R^(a), OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂,—OS(═O)R^(a), —OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a),—OS(═O)₂OR^(a), —OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR),Si(R^(a))(OR^(a))₂, Si(OR^(a))₃, oxo, —N(R^(a))₂, —N═C(R^(a))₂, ═NR^(a),—NC, —NCO, —N₃, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a),—NR^(a)C(═O)N(R^(a))₂, —NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR^(a),—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),NR^(a)S(═O)₂N(R^(a))₂, —SR, —SCN, —S(═O)R^(a), —S(═O)OR,—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂,—SeR^(a), halogen, —CN, —C(═NR^(a))R^(a), —C(═NR^(a))OR^(a),—C(═NR^(a))N(R^(a))₂, —C(═^(a))R^(a), C(═O)OR^(a), C(═O)SR^(a),—C(═S)OR, or —C(═O)N(R^(a))₂;

or the two instances of R^(H) of one or more instances of

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring; and

each instance of R^(a) is independently hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted alkenyl, substitutedor unsubstituted alkynyl, substituted or unsubstituted, monocycliccarbocyclyl, substituted or unsubstituted, monocyclic heterocyclyl,substituted or unsubstituted, monocyclic aryl, substituted orunsubstituted, monocyclic heteroaryl, a nitrogen protecting group whenattached to a nitrogen atom, an oxygen protecting group when attached toan oxygen atom, or a sulfur protecting group when attached to a sulfuratom, or two instances of R^(a) are joined to form substituted orunsubstituted heterocyclyl or substituted or unsubstituted heteroaryl.

In certain embodiments, each instance of the first monomer isindependently of Formula (D1) or (D2):

or a salt thereof, wherein:

each instance of x is independently 0, 1, or 2; and

each instance of y is independently 0, 1, or 2.

In certain embodiments, at least one instance of Z is C(R^(P))₂. Incertain embodiments, each instance of Z is C(R^(P))₂. In certainembodiments, at least one instance of Z is CH₂. In certain embodiments,each instance of Z is CH₂.

In certain embodiments, each instance of R^(P) is hydrogen. In certainembodiments, at least one instance of R^(P) is hydrogen. In certainembodiments, at least one instance of R^(P) is halogen. In certainembodiments, at least one instance of R^(P) is unsubstituted, C₁₋₆ alkylor C₁₋₆ alkyl substituted with one or more halogen. In certainembodiments, at least one instance of R^(P) is unsubstituted methyl.

In certain embodiments, at least one instance of R^(H) is hydrogen. Incertain embodiments, each instance of R^(H) is hydrogen.

In certain embodiments, at least one instance of R^(H) is substituted orunsubstituted alkyl (e.g., —CF₃). In certain embodiments, at least oneinstance of R^(H) is —CN. In certain embodiments, at least one instanceof R^(H) is —C(═O)OR^(a) (e.g, —C(═O)OCH₃). In certain embodiments, atleast one instance of R^(H) is —C(═O)R^(a). In certain embodiments, atleast one instance of R^(H) is —C(═O)N(R^(aa))₂.

In certain embodiments, each instance of the linear units is of theformula:

In certain embodiments, each instance of the first monomer is of Formula(D).

In certain embodiments, each instance of the first monomer is of theformula:

In certain embodiments, each instance of the first monomer is of theformula:

In certain embodiments, the two instances of R of one or more instancesof

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic carbocyclic ring, orsubstituted or unsubstituted, monocyclic heterocyclic ring. In certainembodiments, the two instances of R^(H) of one or more instances of

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic cycloalkenyl ring. In certainembodiments, the two instances of R^(H) of one or more instances of

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic, saturated heterocyclic ring.In certain embodiments, at least one instance of the first monomercomprises a substituted or unsubstituted partially unsaturatedmonocyclic carbocyclic ring or a substituted or unsubstituted partiallyunsaturated monocyclic heterocyclic ring.

In certain embodiments, each instance of the linear units is of theformula:

In certain embodiments, each instance of the first monomer is of Formula(D2).

In certain embodiments, each instance of x is 0. In certain embodiments,each instance of x is 1. In certain embodiments, each instance of x is2.

In certain embodiments, each instance of y is 1. In certain embodiments,each instance of y is 0. In certain embodiments, each instance of y is2.

In certain embodiments, each instance of x is 1, and each instance of yis 1. In certain embodiments, each instance of x is 1, and each instanceof y is 0. In certain embodiments, each instance of x is 0, and eachinstance of y is 1.

In certain embodiments, each instance of the first monomer is of theformula:

In certain embodiments, each instance of the first monomer is of theformula:

In certain embodiments, each instance of the first monomer is of theformula:

In certain embodiments, at least one instance of R^(J) is —OH. Incertain embodiments, each instance of R^(J) is —OH. In certainembodiments, at least one instance of R^(J) is —OR^(a), provided thatR^(a) is not H. In certain embodiments, at least one instance of R^(J)is —OCN. In certain embodiments, at least one instance of R^(J) is—OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)), —OSi(R^(a))(OR^(a))₂, or —OSi(OR)₃.In certain embodiments, at least one instance of R^(J) is —NH₂. Incertain embodiments, at least one instance of R^(J) is —NHR^(a),provided that R^(a) is not H. In certain embodiments, at least oneinstance of R^(J) is —N(R^(a))₂, provided that R^(a) is not H. Incertain embodiments, at least one instance of R^(J) is —N₃. In certainembodiments, at least one instance of R^(J) is —NC. In certainembodiments, at least one instance of R^(J) is —NCO. In certainembodiments, at least one instance of R^(J) is —SH. In certainembodiments, at least one instance of R^(J) is —SR, provided that R^(a)is not H. In certain embodiments, at least one instance of R^(J) is—SCN. In certain embodiments, at least one instance of R^(J) is —SeH. Incertain embodiments, at least one instance of R^(J) is —SeR^(a),provided that R^(a) is not H. In certain embodiments, at least oneinstance of R^(J) is halogen (e.g., F, Cl, Br, or I). In certainembodiments, at least one instance of R^(J) is —CN. In certainembodiments, at least one instance of R^(J) is —N═C(R^(a))₂ or ═NR. Incertain embodiments, at least one instance of R^(J) is oxo. In certainembodiments, at least one instance of R^(J) is —C(═O)R^(a). In certainembodiments, at least one instance of R^(J) is —C(═O)H. In certainembodiments, each instance of R^(J) is —C(═O)H. In certain embodiments,at least one instance of R^(J) is —C(═O)N(R^(a))₂. In certainembodiments, at least one instance of R^(J) is —OC(═S)R^(a), —C(═O)SR,or —C(═S)OR^(a), provided that R^(J) is not H. In certain embodiments,at least one instance of R^(J) is —C(═O)OH. In certain embodiments, atleast one instance of R^(J) is —C(═O)OR^(a), provided that R^(a) is notH. In certain embodiments, at least one instance of R^(J) is—OC(═O)OR^(a). In certain embodiments, at least one instance of R^(J) is—NR^(a)C(═O)OR^(a) or —OC(═O)N(R^(a))₂.

In certain embodiments, at least one instance of R^(S) is hydrogen. Incertain embodiments, each instance of R^(S) is hydrogen. In certainembodiments, at least one instance of R^(S) is —OH. In certainembodiments, at least one instance of R^(S) is —OR, provided that R^(a)is not H. In certain embodiments, at least one instance of R^(S) is—O(substituted or unsubstituted alkyl) (e.g., —OMe).

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, at least one instance of w is 0. In certainembodiments, at least one instance of w is 1. In certain embodiments, atleast one instance of w is 2. In certain embodiments, at least oneinstance of w is 2 or 3. In certain embodiments, at least one instanceof w is 3. In certain embodiments, at least one instance of w is 4.

In certain embodiments, at least one instance of R^(T) is hydrogen. Incertain embodiments, each instance of R^(T) is hydrogen. In certainembodiments, at least one instance of R^(T) is substituted orunsubstituted alkyl.

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, at least one instance of his 0 or 1. In certainembodiments, each instance of h is 0 or 1.

In certain embodiments, at least one instance of i is 0 or 1. In certainembodiments, each instance of i is 0 or 1.

In certain embodiments, in the same repeating unit, the sum of h and iis 1.

In certain embodiments, at least one instance of the functional units isindependently of the formula:

In certain embodiments, the functional oligomer or functional polymercomprises two or more instances of the functional units.

In certain embodiments, at least one instance of the crosslinking unitsis independently of the formula:

In certain embodiments, at least one instance of the crosslinking unitsis independently of the formula:

In certain embodiments, the functional oligomer or functional polymerdoes not comprise one or more instances of the functional units. Incertain embodiments, the functional oligomer or functional polymercomprises one or more instances of the functional units.

In certain embodiments, at least one instance of R^(U) is substituted orunsubstituted alkenyl, wherein the attachment point is a double bond. Incertain embodiments, at least one instance of R^(U) is ═CH-(substitutedor unsubstituted phenyl) or ═CH—O-(substituted or unsubstituted alkyl).

In certain embodiments, at least one instance of the first monomer is ofthe formula:

In certain embodiments, each instance of Y is O. In certain embodiments,each instance of Y is C(R^(Q))₂ (e.g., —CH₂— or —C(CH₃)₂—). In certainembodiments, each instance of Y is —CH₂—

In certain embodiments, at least one instance of R^(Q) is hydrogen. Incertain embodiments, each instance of R^(Q) is hydrogen. In certainembodiments, at least one instance of R^(Q) is halogen (e.g., F). Incertain embodiments, at least one instance of R^(Q) is substituted orunsubstituted, C₁₋₆ alkyl (e.g., —CH₃).

In certain embodiments, each instance of j is 1. In certain embodiments,each instance of j is 2. In certain embodiments, each instance of j is3.

In certain embodiments, each instance of k is 1. In certain embodiments,each instance of k is 2. In certain embodiments, each instance of k is3. In certain embodiments, each instance of k is 0.

In certain embodiments, each instance of j is 1 and each instance of kis 1, each instance of j is 1 and each instance of k is 2, or eachinstance of j is 2 and each instance of k is 2. In certain embodiments,each instance of j is 1 and each instance of k is 2. In certainembodiments, the sum of each instance of j and each instance of k is 3.

In certain embodiments, the C═C double bond in Formula (B) is of Econfiguration. In certain embodiments, the C═C double bond in Formula(B) is of Z configuration.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of R^(K) is independentlyhydrogen, substituted or unsubstituted, C₁₋₆ alkyl, or substituted orunsubstituted phenyl. In certain embodiments, at least one instance ofR^(K) is hydrogen. In certain embodiments, at least one instance ofR^(K) is substituted or unsubstituted C₁₋₆ alkyl. In certainembodiments, each instance of R^(K) is independently substituted orunsubstituted C₁₋₆ alkyl. In certain embodiments, at least one instanceof R^(K) is unsubstituted C₁₋₄ alkyl. In certain embodiments, at leastone instance of R^(K) is unsubstituted C₁₋₃ alkyl. In certainembodiments, each instance of R^(K) is unsubstituted C₁₋₃ alkyl. Incertain embodiments, each instance of R^(K) is Me. In certainembodiments, each instance of R^(K) is Et. In certain embodiments, eachinstance of R^(K) is n-Pr. In certain embodiments, each instance ofR^(K) is i-Pr. In certain embodiments, at least one instance of R^(K) issubstituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, or substituted orunsubstituted heteroaryl. In certain embodiments, each instance of R^(K)is independently substituted or unsubstituted carbocyclyl, substitutedor unsubstituted heterocyclyl, substituted or unsubstituted aryl, orsubstituted or unsubstituted heteroaryl. In certain embodiments, atleast one instance of R^(K) is substituted or unsubstituted phenyl. Incertain embodiments, each instance of R^(K) is independently substitutedor unsubstituted phenyl. In certain embodiments, at least one instanceof R^(K) is unsubstituted phenyl. In certain embodiments, each instanceof R^(K) is unsubstituted phenyl. In certain embodiments, one instanceof R^(K) is substituted or unsubstituted C₁₋₆ alkyl, and the otherinstance of R^(K) is substituted or unsubstituted phenyl. In certainembodiments, at least one instance of R^(K) is —OR^(N) (e.g.,—O(unsubstituted C₁₋₆ alkyl)). In certain embodiments, each instance ofR^(K) is —OR^(N) (e.g., —O(unsubstituted C₁₋₆ alkyl)).

In certain embodiments, at least one instance of R^(N) is substituted orunsubstituted, C₁₋₆ alkyl, or substituted or unsubstituted phenyl. Incertain embodiments, each instance of R^(N) is independently substitutedor unsubstituted, C₁₋₆ alkyl, or substituted or unsubstituted phenyl. Incertain embodiments, each instance of R^(N) is unsubstituted C₁₋₃ alkylor unsubstituted phenyl. In certain embodiments, each instance of R^(N)is unsubstituted methyl. In certain embodiments, each instance of R^(N)is unsubstituted ethyl. In certain embodiments, each instance of R^(N)is unsubstituted propyl (e.g., isopropyl). In certain embodiments, eachinstance of R^(N) is unsubstituted phenyl. In certain embodiments, atleast one instance of R^(N) is hydrogen. In certain embodiments, atleast one instance of R^(N) is halogen. In certain embodiments, at leastone instance of R^(N) is substituted or unsubstituted, C₁₋₁₀ alkyl. Incertain embodiments, at least one instance of R^(N) is an oxygenprotecting group. In certain embodiments, at least one instance of R^(N)is substituted or unsubstituted carbocyclyl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted aryl, orsubstituted or unsubstituted heteroaryl.

In some embodiments, each instance of the second monomer has a molecularweight between 110 g/mol and 320 g/mol, inclusive. In some embodiments,each instance of the second monomer has a molecular weight between 110g/mol and 200 g/mol, inclusive.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, each instance of the second monomer is of theformula:

or a salt thereof.

In certain embodiments, the functional oligomer or functional polymer,hydroxylated polymer, or copolymer is crosslinked. In certainembodiments, the functional oligomer or functional polymer iscrosslinked because it comprises one or more instances of thecrosslinking units. In certain embodiments, the crosslinking degree ofthe hydroxylated polymer is about 12% mole:mole. In certain embodiments,the crosslinking degree of the hydroxylated polymer is between 10% and15%, inclusive, mole:mole. In certain embodiments, the crosslinkingdegree of the hydroxylated polymer is between 5% and 20%, inclusive,mole:mole. In certain embodiments, the crosslinking degree is between 5%and 10%, inclusive, mole:mole. In certain embodiments, the crosslinkingdegree is between 10% and 15%, inclusive, mole:mole. In certainembodiments, the crosslinking degree is between 15% and 20%, inclusive,mole:mole. In certain embodiments, the crosslinking degree is notgreater than the concentration of all the instances of the secondmonomer in the functional oligomer or functional polymer, hydroxylatedpolymer, or copolymer, mole:mole.

In certain embodiments, the functional polymer is a thermosettingpolymer. In certain embodiments, the hydroxylated polymer is athermosetting polymer. In certain embodiments, the copolymer is athermosetting polymer.

In certain embodiments, the aqueous solubility of the functionaloligomer or functional polymer is between 0.1 and 0.3, between 0.3 and1, between 1 and 3, between 3 and 10, between and 30, or between 30 and100, inclusive, g/L, at 1 atmosphere and 20° C. In certain embodiments,the aqueous solubility of the functional oligomer or functional polymeris between 1 and 10, inclusive, g/L, at 1 atmosphere and 20° C.

In certain embodiments, the aqueous solubility of the hydroxylatedpolymer is between 0.1 and 0.3, between 0.3 and 1, between 1 and 3,between 3 and 10, between 10 and 30, or between 30 and 100, inclusive,g/L, at 1 atmosphere and 20° C. In certain embodiments, the aqueoussolubility of the hydroxylated polymer is between 1 and 10, inclusive,g/L, at 1 atmosphere and 20° C.

In certain embodiments, the molar ratio of the one or more instances ofthe first monomer to one or more instances of a second monomer isbetween 1:2 and 2:1, inclusive, 6:1 and 19:1, inclusive, or 5:1 and35:1, inclusive. In certain embodiments, the molar ratio of the one ormore instances of the first monomer to the one or more instances of thesecond monomer is between 1:2 and 2:1, inclusive. In certainembodiments, the molar ratio of the one or more instances of the firstmonomer to the one or more instances of the second monomer is between1:10 and 10:1 (e.g., between 1:5 and 5:1), inclusive. In someembodiments, the molar ratio of the one or more instances of the firstmonomer to the one or more instances of the second monomer is between1:35 and 35:1, inclusive. In some embodiments, the molar ratio of theone or more instances of the second monomer to the one or more instancesof the first monomer is between 1:33 and 1:27, inclusive. In someembodiments, the molar ratio of the one or more instances of the secondmonomer to the one or more instances of the first monomer is between1:17 and 1:11, inclusive. In some embodiments, the molar ratio of theone or more instances of the second monomer to the one or more instancesof the first monomer is between 1:11 and 1:6, inclusive. In certainembodiments, the molar ratio of the one or more instances of the firstmonomer to the one or more instances of the second monomer is about 1:1.

In certain embodiments, the average molecular weight of the functionaloligomer or functional polymer is between 300 Da and 1 kDa, between 1kDa and 3 kDa, between 3 kDa and kDa, between 10 kDa and 100 kDa, orbetween 100 kDa and 1,000 kDa, inclusive. In certain embodiments, theaverage molecular weight of the functional oligomer or functionalpolymer is between 1 kDa and 10 kDa, inclusive. In certain embodiments,the average molecular weight is as determined by gel permeationchromatography. In certain embodiments, the average molecular weight ofthe functional oligomer or functional polymer as determined by gelpermeation chromatography is between 300 Da and 1,000 kDa, inclusive. Incertain embodiments, the average molecular weight of the functionaloligomer or functional polymer as determined by gel permeationchromatography is between 1 kDa and 8 kDa, inclusive.

In certain embodiments, the average molecular weight of the hydroxylatedpolymer is between 300 Da and 1 kDa, between 1 kDa and 3 kDa, between 3kDa and 10 kDa, between 10 kDa and 100 kDa, or between 100 kDa and 1,000kDa, inclusive. In certain embodiments, the average molecular weight ofthe hydroxylated polymer is between 1 kDa and 10 kDa, inclusive. Incertain embodiments, the average molecular weight is as determined bygel permeation chromatography. In certain embodiments, the averagemolecular weight of the hydroxylated polymer as determined by gelpermeation chromatography is between 300 Da and 1,000 kDa, inclusive. Incertain embodiments, the average molecular weight of the hydroxylatedpolymer as determined by gel permeation chromatography is between 1 kDaand 8 kDa, inclusive.

In certain embodiments, the average molecular weight of the copolymer isbetween 10 kDa and 10,000 kDa, inclusive. In certain embodiments, theaverage molecular weight of the copolymer is between 10 kDa and 30 kDa,between 30 kDa and 100 kDa, between 100 kDa and 1,000 kDa, between 1,000kDa and 10,000 kDa, or between 10,000 kDa and 100,000 kDa, inclusive. Incertain embodiments, the average molecular weight of the copolymer isbetween 10 kDa and 100 kDa, inclusive. In certain embodiments, theaverage molecular weight is as determined by gel permeationchromatography. In certain embodiments, the average molecular weight ofthe copolymer as determined by gel permeation chromatography is between10 kDa and 100,000 kDa, inclusive. In certain embodiments, the numberaverage polymerization degree is between 2 and 1,000, inclusive, withrespect to the first monomer: and between 2 and 1,000, inclusive, withrespect to the second monomer. In certain embodiments, the numberaverage polymerization degree is between 10 and 200, inclusive, withrespect to the first monomer; and between 10 and 200, inclusive, withrespect to the second monomer. In certain embodiments, the numberaverage polymerization degree is between 15 and 100, inclusive, withrespect to the first monomer; and between 15 and 100, inclusive, withrespect to the second monomer. In certain embodiments, the numberaverage polymerization degree is between 2 and 1,000, between 10 and1,000, between 100 and 1,000, between 2 and 100, between 10 and 100,between 2 and 10, inclusive, with respect to the first monomer. Incertain embodiments, the number average polymerization degree is between2 and 1,000, between 10 and 1,000, between 100 and 1,000, between 2 and100, between 10 and 100, between 2 and 10, inclusive, with respect tothe second monomer.

In certain embodiments, the dispersity (D) of the copolymer is between 1and 2, between 1.1 and 2, between 1.3 and 2, between 1.5 and 2, between1.1 and 1.5, between 1.1 and 1.3, between 1.3 and 2, between 1.3 and1.5, between 1.5 and 2, inclusive.

In certain embodiments, the average hydrodynamic diameter of thefunctional oligomer or functional polymer is between 1 and 100 nm,inclusive. In certain embodiments, the average hydrodynamic diameter ofthe functional oligomer or functional polymer is between 1 and 10 nm,inclusive. In certain embodiments, the average hydrodynamic diameter ofthe functional oligomer or functional polymer is between 10 and 30 nm,inclusive. In certain embodiments, the average hydrodynamic diameter ofthe functional oligomer or functional polymer is between 30 and 100 nm,inclusive. In certain embodiments, the average hydrodynamic diameter ofthe hydroxylated polymer is between 1 and 100 nm, inclusive. In certainembodiments, the average hydrodynamic diameter of the hydroxylatedpolymer is between 1 and 10 nm, inclusive. In certain embodiments, theaverage hydrodynamic diameter of the hydroxylated polymer is between 10and 30 nm, inclusive. In certain embodiments, the average hydrodynamicdiameter of the hydroxylated polymer is between 30 and 100 nm,inclusive. In certain embodiments, the average hydrodynamic diameter isas determined by diffusion ordered spectroscopy (DOSY).

In certain embodiments, the copolymer is a block copolymer, preferably ablock polymer comprising at least four consecutive blocks, wherein:

each of the first consecutive block and the third consecutive blockindependently comprises one or more repeating units formed from thefirst monomer or the third monomer if present; and

each of the second consecutive block and the fourth consecutive blockindependently comprises one or more repeating units formed from thesecond monomer.

In certain embodiments, the copolymer is a random copolymer.

In certain embodiments, the step of polymerizing is substantially free(e.g., between 90%/6-99% free) of a chain transfer agent.

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing at least 50% of the —O—Si bonds of the copolymer to form—OH. In certain embodiments, the step of hydrolyzing the copolymercomprises hydrolyzing between 50% and 70%, inclusive, of the —O—Si bondsof the copolymer to form —OH. In certain embodiments, the step ofhydrolyzing the copolymer comprises hydrolyzing between 70% and 90%,inclusive, of the —O—Si bonds of the copolymer to form —OH. In certainembodiments, the step of hydrolyzing the copolymer comprises hydrolyzingbetween 90% and 99%, inclusive, of the —O—Si bonds of the copolymer toform —OH. In certain embodiments, the step of hydrolyzing the copolymercomprises hydrolyzing at least 95% of the —O—Si bonds of the copolymerto form —OH.

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing at least 50% of

of the copolymer to form

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing between 50% and 70%, inclusive, of

of the copolymer to form

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing between 70% and 90%, inclusive, of

of the copolymer to form

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing between 90% and 99%, inclusive, of

of the copolymer to form

In certain embodiments, the step of hydrolyzing the copolymer compriseshydrolyzing at least 95% of

of the copolymer to form

In certain embodiments, the step of hydrolyzing the copolymer comprisesambient temperature, ambient pressure, and a reaction time of between 1hour and 48 hours (e.g., between 1 hour and 6 hours, between 6 hour and24 hours, between 24 hour and 48 hours), inclusive.

In certain embodiments, the step of hydrolyzing the copolymer comprisesreacting the copolymer with a fluoride source. In certain embodiments,the fluoride source is tetra(unsubstituted alkyl)-ammonium fluoride. Incertain embodiments, the fluoride source is tetra(unsubstituted C₁₋₆alkyl)-ammonium fluoride (e.g., TBAF). In certain embodiments, thefluoride source is a metal fluoride (e.g., alkali metal fluoride oralkaline earth metal fluoride). In certain embodiments, a polymer ischemically degradable in the presence of tetra-n-butylammonium fluoride(TBAF).

In some embodiments, the amount of the fluoride source is about 1equivalent (mole:mole) relative to the amount of the second monomer. Insome embodiments, the amount of the fluoride source is in excess (e.g.,about 2 equivalents) relative to the amount of the second monomer.

In certain embodiments, the step of hydrolyzing the copolymer comprisesreacting the copolymer with an acid.

In certain embodiments, the acid is an aqueous solution of an acid. Incertain embodiments, the acid is an inorganic acid. In certainembodiments, the acid is an organic acid. In certain embodiments, theacid has a pKa value of less than 3, less than 2, less than 1, or lessthan 0, under ambient conditions. In certain embodiments, the acid isHCl, HBr, HI, HClO₄, HNO₃, H₂SO₄, CH₃SO₃H, or CF₃SO₃H. In certainembodiments, the acid is HCl. In certain embodiments, the acid isCF₃CO₂H.

In some embodiments, the amount of the acid is about 1 equivalent(mole:mole) relative to the amount of the second monomer. In someembodiments, the amount of the acid is in excess (e.g., about 2equivalents) relative to the amount of the second monomer.

In another aspect, the present disclosure describes compositionscomprising:

a hydroxylated polymer; and

optionally an excipient.

Compositions described herein can be prepared by any method known in theart. In general, such preparatory methods include bringing thehydroxylated polymer into association with an excipient, and/or one ormore other accessory ingredients, and then, if necessary and/ordesirable, shaping, and/or packaging the product into a desired unit.

In another aspect, the present disclosure describes kits comprising:

a hydroxylated polymer; and

instructions for using the hydroxylated polymer.

Kits may be commercial packs or reagent packs. The kits may furthercomprise a container (e.g., a vial, ampule, bottle, syringe, and/ordispenser package, or other suitable container). In certain embodiments,a kit further comprises instructions for using the hydroxylated polymer(e.g., for preparing a conjugate).

Conjugates, and Methods of Preparation. Compositions, and Kits Thereof

In another aspect, the present disclosure describes conjugates preparedby reacting a hydroxy-reacting substance with a hydroxylated polymerdescribed herein, wherein hydroxy-reacting substance comprises at leastone instance of a hydroxy-reacting moiety.

In another aspect, the present disclosure describes methods of preparinga conjugate comprising reacting a hydroxy-reacting substance with ahydroxylated polymer described herein, wherein hydroxy-reactingsubstance comprises at least one instance of a hydroxy-reacting moiety.

In certain embodiments, the hydroxy-reacting substance is ahydroxy-reacting small molecule. In certain embodiments, thehydroxy-reacting substance is lactide. In certain embodiments, thehydroxy-reacting substance is a hydroxy-reacting polymer. In certainembodiments, the average molecular weight of the hydroxy-reactingpolymer is between 1 kDa and 3 kDa, between 3 kDa and 10 kDa, between 10kDa and 30 kDa, between 30 kDa and 100 kDa, or between 100 kDa and 1,000kDa, inclusive. In certain embodiments, the average molecular weight ofthe hydroxy-reacting polymer is between 3 kDa and 30 kDa, inclusive. Incertain embodiments, the average molecular weight is as determined bygel permeation chromatography. In certain embodiments, the averagemolecular weight of the hydroxy-reacting polymer as determined by gelpermeation chromatography is between 1 kDa and 1,000 kDa, inclusive.

In certain embodiments, the hydroxy-reacting substance is apolysiloxane, wherein the polysiloxane comprises at least one instanceof a hydroxy-reacting moiety. In certain embodiments, thehydroxy-reacting substance is a polydimethylsiloxane (PDMS), wherein thePDMS comprises at least one instance of a hydroxy-reacting moiety (e.g.,hydride (e.g., Si(IV)-H)).

In certain embodiments, at least one instance of the hydroxy-reactingmoiety is Si(IV)—H, Si(IV)-(a leaving group), C(IV)-(a leaving group),—C(═O)—OH, —C(═O)-(a leaving group), —C(═O)—O—, —C(═O)—O—C(═O)—,—S(═O)—OH, —S(═O)-a leaving group), —S(═O)₂—OH, —S(═O)₂-(a leavinggroup), —OH, or —O-(a leaving group). In certain embodiments, at leastone instance of the hydroxy-reacting moiety is Si(IV)—H. In certainembodiments, at least one instance of the hydroxy-reacting moiety is—C(═O)-(a leaving group). In certain embodiments, at least one instanceof the hydroxy-reacting moiety is —O-(a leaving group).

In certain embodiments, the hydroxy-reacting substance is a polylacticacid (PLA). In certain embodiments, the hydroxy-reacting substance is apolyethylene glycol (PEG).

In another aspect, the present disclosure describes compositionscomprising:

a conjugate; and

optionally an excipient.

Compositions described herein can be prepared by any method known in theart. In general, such preparatory methods include bringing the conjugateinto association with an excipient, and/or one or more other accessoryingredients, and then, if necessary and/or desirable, shaping, and/orpackaging the product into a desired unit.

In another aspect, the present disclosure describes kits comprising:

a conjugate: and

instructions for using the conjugate.

Kits may be commercial packs or reagent packs. The kits may furthercomprise a container (e.g., a vial, ampule, bottle, syringe, and/ordispenser package, or other suitable container). In certain embodiments,a kit further comprises instructions for using the conjugate (e.g., foruse as a bulk material).

Embodiments

Embodiment 1. A hydroxylated polymer prepared by hydrolyzing a copolymerprepared by a method comprising polymerizing in the presence of ametathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is independently of the formula:

or salt thereof, wherein:

-   -   each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring;

-   -   each instance of Z is independently C(R^(P))₂ or O;    -   each instance of R^(P) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆ alkyl; and    -   each instance of        is independently a single bond or double bond; and

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of Formula (B):

or a salt thereof; wherein:

-   -   each instance of Y is independently O or C(R^(Q))₂;    -   each instance of R^(Q) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆alkyl;    -   each instance of R^(K) is independently hydrogen, halogen,        substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or        unsubstituted carbocyclyl, substituted or unsubstituted        heterocyclyl, substituted or unsubstituted aryl, substituted or        unsubstituted heteroaryl, or —OR^(N);    -   each instance of R^(N) is independently hydrogen, substituted or        unsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,        substituted or unsubstituted carbocyclyl, substituted or        unsubstituted heterocyclyl, substituted or unsubstituted aryl,        substituted or unsubstituted heteroaryl, or an oxygen protecting        group;    -   each instance of j is independently 1, 2, or 3; and    -   each instance of k is independently 0, 1, 2, or 3;

wherein any two instances of the first monomer are the same as ordifferent from each other, and any two instances of the second monomerare the same as or different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

Embodiment 2. A method of preparing a hydroxylated polymer comprisinghydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst:

i) one or more instances of a first monomer, wherein each instance ofthe first monomer is independently of the formula:

or salt thereof, wherein:

-   -   each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring;

-   -   each instance of Z is independently C(R^(P))₂ or O;    -   each instance of R^(P) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆alkyl; and    -   each instance of        is independently a single bond or double bond; and

ii) one or more instances of a second monomer, wherein each instance ofthe second monomer is of Formula (B);

or a salt thereof; wherein:

-   -   each instance of Y is independently O or C(RC)₂;    -   each instance of R^(Q) is independently hydrogen, halogen, or        substituted or unsubstituted, C₁₋₆ alkyl;    -   each instance of R^(K) is independently hydrogen, halogen,        substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or        unsubstituted carbocyclyl, substituted or unsubstituted        heterocyclyl, substituted or unsubstituted aryl, substituted or        unsubstituted heteroaryl, or —OR^(N).    -   each instance of R^(N) is independently hydrogen, substituted or        unsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,        substituted or unsubstituted carbocyclyl, substituted or        unsubstituted heterocyclyl, substituted or unsubstituted aryl,        substituted or unsubstituted heteroaryl, or an oxygen protecting        group;    -   each instance of j is independently 1, 2, or 3; and    -   each instance of k is independently 0, 1, 2, or 3;

wherein any two instances of the first monomer are the same as ordifferent from each other, and any two instances of the second monomerare the same as or different from each other; and

wherein the step of hydrolyzing the copolymer comprises hydrolyzing oneor more instances of the —O—Si bonds of the copolymer to form —OH.

Embodiment 3. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the metathesis catalyst is a rutheniummetathesis catalyst.

Embodiment 4. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the metathesis catalyst is a Grubbscatalyst.

Embodiment 5. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the first monomer isindependently of Formula (D1) or (D2):

or a salt thereof, wherein:

each instance of x is independently 0, 1, or 2; and

each instance of y is independently 0, 1, or 2.

Embodiment 6. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein at least one instance of Z is C(R^(P))₂.

Embodiment 7. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of R^(P) is hydrogen.

Embodiment 8. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the first monomer is ofFormula (D1).

Embodiment 9. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the first monomer is ofthe formula:

Embodiment 10. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the first monomer is ofFormula (D2).

Embodiment 11. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of x is 0.

Embodiment 12. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of y is 1.

Embodiment 13. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the first monomer is ofthe formula:

Embodiment 14. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of Y is O.

Embodiment 15. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of j is 1 and each instanceof k is 1, each instance of j is 1 and each instance of k is 2, or eachinstance of j is 2 and each instance of k is 2.

Embodiment 16. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 17. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 18. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 19. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 20. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of R^(K) is independentlyhydrogen, substituted or unsubstituted, C₁₋₆ alkyl, or substituted orunsubstituted phenyl.

Embodiment 21. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of R^(K) is unsubstitutedC₁₋₃ alkyl.

Embodiment 22. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of R^(K) is unsubstitutedphenyl.

Embodiment 23. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 24. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 25. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 26. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 27. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 28. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein each instance of the second monomer is ofthe formula:

or a salt thereof.

Embodiment 29. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the hydroxylated polymer is crosslinked.

Embodiment 30. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the crosslinking degree of thehydroxylated polymer is between 5% and 20%, inclusive, mole:mole.

Embodiment 31. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the hydroxylated polymer is athermosetting polymer.

Embodiment 32. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the molar ratio of the one or moreinstances of the first monomer to one or more instances of a secondmonomer is between 1:2 and 2:1, inclusive, 6:1 and 19:1, inclusive, or5:1 and 35:1, inclusive.

Embodiment 33. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the average molecular weight of thehydroxylated polymer as determined by gel permeation chromatography isbetween 300 Da and 1,000 kDa, inclusive.

Embodiment 34. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the average molecular weight of thecopolymer as determined by gel permeation chromatography is between 10kDa and 100,000 kDa, inclusive.

Embodiment 35. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the average hydrodynamic diameter of thehydroxylated polymer is between 1 and 100 nm, inclusive.

Embodiment 36. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the step of hydrolyzing the copolymercomprises hydrolyzing at least 50% of the —O—Si bonds of the copolymerto form —OH.

Embodiment 37. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the step of hydrolyzing the copolymercomprises ambient temperature, ambient pressure, and a reaction time ofbetween 1 hour and 48 hours, inclusive.

Embodiment 38. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the step of hydrolyzing the copolymercomprises reacting the copolymer with a fluoride source.

Embodiment 39. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the fluoride source istetra(unsubstituted C₁₋₆alkyl)-ammonium.

Embodiment 40. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the step of hydrolyzing the copolymercomprises reacting the copolymer with an acid.

Embodiment 41. The hydroxylated polymer or method of any one of thepreceding embodiments, wherein the acid is HCl.

Embodiment 42. A composition comprising:

-   -   a hydroxylated polymer of any one of any one of the preceding        embodiments; and optionally an excipient.

Embodiment 43. A kit comprising:

-   -   a hydroxylated polymer of any one of any one of the preceding        embodiments; and instructions for using the hydroxylated        polymer.

Embodiment 44. A conjugate prepared by reacting a hydroxy-reactingsubstance with a hydroxylated polymer of any one of the precedingembodiments, wherein hydroxy-reacting substance comprises at least oneinstance of a hydroxy-reacting moiety.

Embodiment 45. A method of preparing a conjugate comprising reacting ahydroxy-reacting substance with a hydroxylated polymer of any one of thepreceding embodiments.

Embodiment 46. The conjugate or method of any one of the precedingembodiments, wherein the hydroxy-reacting substance is ahydroxy-reacting small molecule.

Embodiment 47. The conjugate or method of any one of the precedingembodiments, wherein the hydroxy-reacting substance is lactide.

Embodiment 48. The conjugate or method of any one of the precedingembodiments, wherein the hydroxy-reacting substance is ahydroxy-reacting polymer.

Embodiment 49. The conjugate or method of any one of the precedingembodiments, wherein the average molecular weight of thehydroxy-reacting polymer as determined by gel permeation chromatographyis between 1 kDa and 1,000 kDa, inclusive.

Embodiment 50. The conjugate or method of any one of the precedingembodiments, wherein the hydroxy-reacting substance is a polysiloxane,wherein the polysiloxane comprises at least one instance of ahydroxy-reacting moiety.

Embodiment 51. The conjugate or method of any one of the precedingembodiments, wherein at least one instance of the hydroxy-reactingmoiety is Si(IV)—H, Si(IV)-(a leaving group), C(IV)-(a leaving group),—C(═O)—OH, —C(═O)-(a leaving group), —C(═O)—O—, —C(═O)—O—C(═O)—,—S(═O)—OH, —S(═O)-(a leaving group), —S(═O)₂—OH, —S(═O)₂-(a leavinggroup), —OH, or —O-a leaving group).

Embodiment 52. The conjugate or method of any one of the precedingembodiments, wherein the hydroxy-reacting substance is a polyethyleneglycol.

Embodiment 53. A composition comprising:

a conjugate of any one of the preceding embodiments; and

optionally an excipient.

Embodiment 54. A kit comprising:

a conjugate of any one of the preceding embodiments; and

instructions for using the conjugate.

Examples

In order that the present disclosure may be more fully understood, thefollowing examples are set forth. The synthetic and biological examplesdescribed in this application are offered to illustrate the compounds,pharmaceutical compositions, and methods provided herein and are not tobe construed in any way as limiting their scope.

Materials and Methods

All reagents were purchased from commercial suppliers and used withoutfurther purification unless otherwise noted. Grubbs 2^(nd) Generationcatalyst was purchased from Sigma-Aldrich, dissolved in drydichloromethane, concentrated under vacuum, and finely powderedimmediately before use.

¹H nuclear magnetic resonance (¹H-NMR) and ¹³C nuclear magneticresonance (¹³C-NMR) spectra were acquired at the MIT Department ofChemistry Instrumentation Facility on a Varian Mercury 300, BrukerAVANCE III DRX 400, or a Varian Inova 500. Chemical shifts are reportedin ppm relative to signals from the NMR solvent: for CDCl₃, thiscorresponds to 7.26 for ¹H and 77.0 for ¹³C spectra. Solid state NMR wasperformed on a Bruker AVANCE III501. High-resolution mass spectrometry(HRMS) measurements were obtained on a JEOL AccuTOF system at the MITDepartment of Chemistry Instrumentation Facility. GPC analysis wasperformed on a Tosoh EcoSEC HLC-8320 with dual TSKgel SuperH3000 columnsand a chloroform mobile phase at a flow rate of 1 mL/min. Molecularweight calculations were performed using linear polystyrene standards.

Preparation of Monomers

The monomers were prepared according to the methods described in U.S.patent application Ser. No. 16/542,824.

Preparation of Copoymers

The copolymers were prepared according to the methods described in U.S.patent application Ser. No. 16/542,824.

Preparation of Hydroxylated Polymers

200 μL pellets of a copolymer where the first monomer is DCPD was placedin 5 mL of THF. Next, sufficient amounts of TBAF were added for 2equivalents relative to the second monomer. The mixture was allowed tosit for 12 hours, after which the mixture almost completely dissolved.The mixture were carefully transferred to another vial to separate themfrom any residual solids and then concentrated under reduced pressure.The residue was then analyzed by NMR and GPC. To removetetrabutylammonium salts, which interfered with DOSY and 2D NMRanalysis, a THF solution of the residue was incubated with an excess ofH-Dowex resin and calcium carbonate and filtered following literatureprotocol (36).

Surface Mechanical Measurements by Nanoindentation

Mechanical testing was performed on a Tribolndenter (Hysitron) using aBerkovich diamond tip. Indentations were performed using a sequence of10 s approach, 10 s static hold, and 10 s departure. Indentation depthsof 300 and 1000 nm were performed to explore the influence ofindentation depth on material mechanical properties. Experiments wereperformed at the MIT Department of Materials Science and EngineeringNanoMechanical Technology Laboratory.

Weathering Experiments

To assess plastic degradability under marine environment, a majorpotential application area for degradable pDCPD, we exposed the materialto 300 nm UV light in a synthetic seawater matrix (37). We hypothesizedthat photooxidation of iPrSi-doped pDCPD would further enhance theaqueous solubility by introducing oxygen functional groups, assistingthe hydrolysis of silyl ether groups. Around 100 mg of polymer pelletwas submerged in the bottom of 60 mL synthetic seawater matrix in aclear vial sealed with PTFE-lined cap. The vial was then exposed to 300nm UV light, providing a maximum of 0.19 W/m² between 280-320 nm(measured by OceanInsight FLAME-S-XR-ES spectroradiometer), in a Rayonetreactor for 16 days. Solar irradiance between 280-320 nm was used as areference (ATSM G173-03 reference spectra) to estimate the longevity ofmaterials under realistic solar condition. We calculated degradation asthe mass of carbon released in the seawater solution over the mass ofcarbon in the original material, with the assumption of a constantdegradation rate. Total organic carbon was measured as non-purgableorganic carbon by Shimazu TOC-5000. Prior to analysis, the sample wasacidified with 50% HC to pH<3 and sparged with N₂ for 8 min to removeinorganic carbon in seawater matrix. Total organic carbon in the virginpolymer was inferred from chemical formula and mass fraction of iPrSi orEtSi co-monomers. A paired t-Test was performed to determine whethercontent of iPrSi or light exposure has an impact on degradability.

TABLE 1 Statistical analysis of weathering experiments. P value (0.05Comparative group Test n significance level) Light 0% vs 10% iPrSi Twosample t-Test 3 7.4 × 10⁻⁴ Light 0% vs 20% iPr-Si Two sample t-Test 30.001 Light 10% vs 20% iPr-Si Two sample t-Test 3 0.005 Light 10% EtSivs 10% iPrSi Two sample t-Test 3 0.001 Dark 0% vs 10% iPrSi Two samplet-Test 3 0.02 Dark 0% vs 20% iPrSi Two sample t-Test 3 0.001 Dark 10% vs20% iPrSi Two sample t-Test 3 0.06 Dark 10% EtSi vs 10% iPrSi Two samplet-Test 3 0.26 Light vs Dark Two sample t-Test 12  2.9 × 10⁻⁷ 0% iPrSiLight vs Dark Two sample t-Test 3 2.9 × 10⁻⁴ 10% iPrSi Light vs Dark Twosample t-Test 2 1.4 × 10⁻⁴ 209 iPrSi Light vs Dark Two sample t-Test 34.3 × 10⁻⁴ 10% EtSi Light vs Dark Two sample t-Test 3 2.6 × 10⁻⁵

TABLE 2 Mass of carbon released into seawater matrix during 16 days ofUV light exposure. Doped pDCPD Light Dark g C released / Standard g Creleased / Standard g C in polymer deviation g C in polymer deviation 0%iPrSi 0.0033 0.0003 0.0005 0.0002 10% iPrSi 0.0052 0.0001 0.0015 0.000320% iPrSi 0.0081 0.0007 0.0023 0.0007 10% EtSi 0.0073 0.0003 0.00190.0007

Seawater matrix blank has an organic carbon content of 0.73+/−0.06 mg/Land was subtracted when presenting the dissolved carbon in sampleincubated with pDCPD pellets. All samples were measured in triplicate.

Gel Permeation Chromatography

A hydroxylated polymer where the first monomer is DCPD was dissolved inCHChl₃ at a concentration of 2 mg/mL. The solution was then filteredthrough a 0.2 μm Teflon filter before analysis. GPC analysis wasperformed on a EcoSEC HLC-8320 (Tosoh) with dual TSKgel SuperH3000columns and a chloroform mobile phase at a flow rate of 1 mL/min.Molecular weight calculations were performed using linear polystyrenestandards.

Transmission Electron Microscopy

A dilute solution of a hydroxylated polymer where the first monomer isDCPD and the second monomer is 10% iPrSi (prepared from TBAF dissolutionof the copolymer followed by Dowex/CaCO₃ clean-up) in DCM was dropcastonto a copper grid and stained with RuO4 vapors. The samples were thenimaged on an FEI Tecnai transmission electron microscope.

Synthesis of PLA-Containing Conjugates

50 mg of a hydroxylated polymer where the first monomer is DCPD and 500mg of rac-lactide were dissolved in 2 mL of dry THF. Next, 20 μL of 1 MDBU in THF was added and the reaction mixture was allowed to stir at RTfor 2 hours. The reaction was then quenched with 1 mg of benzoic acidand precipitated into MeOH to yield 153 mg of the PLA-containingconjugates as a white solid.

Synthesis of PEG-Containing Conjugates

50 mg of a hydroxylated polymer where the first monomer is DCPD weredissolved in 500 μL of dry DCM and cooled to 0° C. Next, 10 mg ofpara-nitrophenyl chloroformate was added, followed by 50 μL of pyridine.The reaction was allowed to stir at RT for 1 hour. Next, to the reactionwas added 130 mg of α-amino-ω-hydroxy-polyethylene glycol (averagemolecular weight of 3000) and 50 μL of triethylamine. The reaction wasallowed to stir at RT for another 30 minutes, then concentrated andrediluted in 1 mL of THF. Another 50 μL of triethylamine was added andthe reaction was heated to 50° C. and stirred under nitrogen for 12hours. The material was then concentrated under vacuum, taken up in 4 mLDCM, washed with 2×2 mL 0.1 M HCl, 2×2 mL sat. NaHCO₃, and 2×2 mL 0.1 MNaOH before drying with sodium sulfate and concentrating to yield thePEG-containing conjugates as a pale yellow solid.

Synthesis of PDMS-Containing Conjugates

190.5 mg (0.174 mmol OH) of a hydroxylated polymer where the firstmonomer is DCPD were added to a 5 mL vial. Next, 1 mL of dry DCM and35.8 μL (0.261 mmol) triethylamine were added and the mixture stirredunder nitrogen. After all reagents had fully dissolved, the mixture wascooled to 0° C. To this mixture was slowly added 49.7 mg (0.157 mmol) ofneat 1-chloro-1,1,3,3,5,5,7,7-octamethyltetrasiloxane. The material wasthen warmed to RT and stirred for 1 hour. The material was then dilutedwith 20 mL of DCM and washed 2× with 0.0001 M HCl, 3× with water, 2×brine, and dried under vacuum. The fragments were triturated three timeswith hexanes to remove any unreacted tetrasiloxane and dried undervacuum to yield 201.6 mg (85%) of PDMS-containing conjugates.

Synthesis of PDMS-Containing Conjugates

PDMS starting materials were degassed by removing the product lids andplacing under vacuum for 3 days. 5.05 g (5.46 mmol Si—CH═CH₂) ofdegassed 28 kDa 8% vinyl functionalized PDMS was added into a 40 mLvial. Next, 21.5 g (2.53 mmol Si—H) of degassed 17 kDa dihydride PDMSwas added to achieve a molar ratio of silyl hydride to vinyl silane ofroughly 1:2, leaving excess vinyl groups available for furthermodification. This master mix was slowly stirred for 2 hours to ensurefull mixing of components without the introduction of addition air intothe sample. During this time, 24.3 mg of the PDMS-containing conjugatesof the above example (˜0.017 mmol Si—H) were dissolved in 5 mL of DCM.In a separate vial, 4.00 g of the PDMS master mix was blended with 5 mLDCM. To this solution was added the PDMS-containing conjugates solutionand the mixture was immediately vortexed for 1 minute. The mixture wasthen immediately concentrated under rotary evaporation at 50° C. for 20minutes, then for 3 minutes on a Schlenk apparatus to fully remove DCM.Finally, 20 μL Karstedt's catalyst solution in xylenes (2 wt % platinum,Sigma Aldrich) was added and the PDMS mixture vortexed for 2 minutes.The material was poured into folded PTFE liners (˜1×1×0.25 inch) andcured in a vacuum oven at 70° C. for 12 hours. The low relative Si—Hfunctionality found in pDCPD dopants relative to the network mixsuggests that mechanical improvements are due to the physical presenceof pDCPD and not increased crosslinking density.

Dynamic Mechanical Analysis of Composites

DMA was performed on a Discovery DMA 850 System (TA). Samples withdimensions ca. 1.5×1.5×8 mm (w×t×1) were tested in tension mode.Measurements were recorded at a frequency of 1 Hz, an amplitude of 10 μmfrom −90 to 40° C. at a rate of 3° C. min-1 with a data samplinginterval of 3 s/pt using a 125% force tracking and 0.01 N preload force.DMA data were obtained using Trios software and exported to MicrosoftExcel for analysis. Experiments were performed at the MIT Institute forSoldier Nanotechnologies. The reported modulus at 25° C. was determinedby averaging measurements from 20° C. to 30° C., while the modulus at−70° C. is reported as is.

Discussion

The products of degradation of our iPrSi-doped samples represent a newclass of low-cost densely hydroxylated, alkene-functionalizedhydrocarbon frameworks with numerous potential opportunities forrepurposing and/or upcyling (FIGS. 3c, 3d ). The size of these fragmentscan be readily tuned by modifying the iPrSi loading. Diffusion orderedspectroscopy (DOSY) was used to further study this relationship, showinga clear trend between particle size and the amount of iPrSi used. FromDOSY, we estimate that the average hydrodynamic diameter of thefragments obtained from the 10% iPrSi-doped pDCPD sample was ˜4 nm,which was further corroborated by TEM imaging (FIG. 3d , FIG. 10).

The excellent mechanical properties of pDCPD suggest that utilizingthese degradation fragments as fillers for other materials may yieldcomposites with improved mechanical properties.

To test this hypothesis, we explored their potential as fillers foranother industrially relevant class of thermosets: silicone elastomers.Hydride-terminated 350 Da polydimethylsiloxane (PDMS) was covalentlygrafted to the surface of the pDCPD fragments through nucleophilicsubstitution; successful conjugation was confirmed by DOSY NMR (FIGS.11A-11B). Filled PDMS elastomers were prepared using varying amounts ofthe PDMS-grafted pDCPD fragments as fillers through platinum-catalyzedhydrosilylation of 17.2 kDa Si—H terminated PDMS and a 28 kDa linearPDMS bearing 8% vinyl functionality. The mechanical properties of theelastomers were characterized through constant frequency temperaturesweeps using DMA (FIG. 3e ). The PDMS-grafted fragments showed improvedmiscibility with PDMS, and, notably, the filled materials displayedsignificantly increased storage moduli at only 0.5 wt % loading (FIG. 3f, FIG. 12).

To further illustrate the broad chemical versatility of these pDCPDfragments, we employed them as macroinitiators for the growth ofpolylactide (FIGS. 13-14), a commodity polyester, and as scaffolds forcovalent conjugation of polyethylene glycol, a commonly used biomaterial(FIGS. 15-16). Altogether, these results hint at many new opportunitiesto repurpose or upcycle pDCPD that are enabled by our simple co-monomerstrategy.

In summary, we describe a co-monomer strategy to prepare upcyclableversions of the industrially-relevant thermoset pDCPD. The low potentialcost of our co-monomer and the small amount needed to endow pDCPD withupcyclability paves a path toward the broader deployment of thisapproach to larger scales. Moreover, our finding that the installationof cleavable bonds into strands versus crosslinks provides a designprinciple that should be applicable to many other thermosetting systems.While thermosets have served as a pillar of the plastics and rubberindustries since their first description in the early₂₀th century, ourapproach, which is uniquely enabled by recent innovations in polymerchemistry, may breathe new life into these old materials and address theconcerns broadly facing 21′ century materials design challenges.

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Cleavable Comonomers Enable Degradable, Recyclable Thermoset PlasticsTheoretical Framework for Degradable Thermosets Via Copolymerization

To estimate the amount of cleavable comonomer x required to degradenetworks of strands with f crosslinkable functional groups and ccrosslinks into soluble products, we derived a reverse gel-point modelbased on Miller-Macosko²³ and Flory-Stockmayer^(24,25) theories (FIG.17B, FIGS. 21A-21B; see Methods, below):

$x > \frac{{c( {{2f} - 1} )} - f}{c + f}$

From this equation, it is observed that when f>>c, degradation intosoluble products is expected when x>˜2c. If it was instead assumed thatthat f≈c, then degradation to soluble products is expected when:

x>c−1

Thus, the model predicts what is also intuitive: degradation ofthermosets to soluble products can be achieved when the number ofcleavable bonds in strands is similar in magnitude to the number ofcrosslinks. This model assumes that the cleavable bonds are randomlydistributed along strands, that equivalent functional groups have equaland independent reactivity, and that there are no intramolecularreactions; thus, it provides an estimate of x—the presence of loops thatconsume functionality yet do not contribute to gelation will furtherlower the number of degradable bonds needed to achieve degradation (videinfra).²⁶Cleavable Bond Location Determines Degradability in pDCPD

To test the validity of this model, recently reported silyl ethermonomers that copolymerize with norbornene derivatives by ROMP wereleveraged to produce degradable statistical copolymers.¹⁷Here, DCPD wasmixed with different amounts of the silyl ether monomer iPrSi (0, 5, 10,or 15% v/v or one equivalent of iPrSi per 30.8, 14.6, and 9.2equivalents of DCPD, respectively, FIG. 17C); the mixtures were cured inthe presence of Grubbs 2^(nd)-generation ROMP initiator. While thiscuring protocol was not further optimized, the resulting materialsdisplayed Young's moduli in the GPa range (vide infra) as expected forpDCPD thermosets. In the initial stage of pDCPD curing, the norbornenecomponent of DCPD copolymerizes with iPrSi to form linear polymerstrands with f cyclopentene sidechains as potential crosslinking sitesand x cleavable silyl ether linkages (FIG. 17C). Cyclopentene sidechainmetathesis leads to iPrSi-doped pDCPD with c crosslinks. Silyl ethercleavage is expected to generate fragments with <c/x+1> crosslinks perstrand, thus, as x approaches c, smaller soluble products should beproduced. This approach stands in contrast to the indiscriminatedegradation of thermosets, which produces products ofuncontrolled sizeand chemical composition that typically have much lower value: thecomonomer strategy provides a way to trigger thermoset degradation atlow comonomer loadings and control degradation product size andcomposition (vide infra). Lastly, a preliminary techno-economic analysissuggested that iPrSi can be manufactured inexpensively, making itpotentially feasible for large-scale use especially if added as anadditive to existing pDCPD workflows.

To compare iPrSi-doped pDCPD to analogs with cleavable crosslinks, pDCPDsamples were prepared in the presence of up to 80% v/v of abis-cyclooctene crosslinker featuring a silyl ether linkage (SiXL, FIG.17D). In this case, the addition of y cleavable crosslinks (from SiXL)was expected to yield thermosets with c+y crosslinks; cleavage of the ylinkages leaves a network with c crosslinks, precluding the formation ofsoluble products for all y values other than those much greater than c(FIG. 17D). In thermosetting materials with mostly cleavable crosslinks,theoretically it is possible, though often difficult in practice, toachieve material degradation once nearly all of the crosslinks arecleaved.⁹ For thermosets that lack naturally cleavable crosslinks,however, the addition of a small number of cleavable crosslinks is notexpected to produce degradable materials.

To test this hypothesis, samples of iPrSi-doped, SiXL-doped, and nativepDCPD (FIG. 18A, FIGS. 22A-22C) were exposed to an excess oftetrabutylammonium fluoride (TBAF), a fluoride reagent that selectivelycleaves silyl ethers and is often used to etch silicone elastomers,²⁷ atroom temperature. After 12 h, the native pDCPD remained fully intact(FIG. 18B). In contrast, samples with only 10 or 15% v/v iPrSi dissolved(FIGS. 18A-18B). While the 5% iPrSi-doped sample remained intact, it wasnoticeably swollen, suggesting a decrease in crosslink density that wasfurther confirmed by analysis of Si content using ICP-OES (FIG. 38. Ineach case, degradation of the iPrSi-doped samples occurred over thecourse of ˜4 h, presumably limited by fluoride diffusion into thematerials (FIGS. 39A-39B). Meanwhile, SiXL-doped materials did notdegrade into soluble products even at 80% SiXL loading (FIG. 18B, FIGS.22A-22C, FIG. 58). The rate of SiXL cleavage by fluoride was observed tobe similar to that of iPrSi, suggesting that this difference in extentof degradation is due to network topology.

To further compare the roles of cleavable strands versus crosslinks inthese materials, samples of 5% v/v and 10% v/v iPrSi and 20% v/v SiXLdoped pDCPD were swollen to equilibrium in tetrahydrofuran (THF) andcharacterized by oscillatory rheology (FIG. 1C, FIGS. 23A-23C, FIG. 59).Strikingly, treatment of the iPrSi-doped samples with TBAF led to largedecreases in storage modulus (˜100-fold for 5% iPrSi doped pDCPD) whilethe modulus of the 20% v/v SiXL-doped sample decreased by only ˜5-fold.

Functional Evaluation of pDCPD Samples with Degradable Strands

Next, the functional performance of iPrSi-doped pDCPD was studied forcomparison to the native material. In tensile tests, the 10% and 20%iPrSi-doped samples showed nearly identical Young's moduli andelongations at break compared to pDCPD (FIGS. 19A-19C, FIG. 60) while33% and 50% iPrSi-doped samples showed much lower moduli. These resultswere corroborated by dynamic mechanical analyses (DMA) andnanoindentation studies (FIG. 19D, FIG. 2A,). Thermal gravimetricanalysis (TGA) showed similar decomposition temperatures for all samples(FIG. 19E). DMA showed a modest decline in T_(g) from 166° C. for nativepDCPD to 138° C. for the 10% iPrSi-doped sample and a further T_(g)lowering for higher iPrSi loadings (FIG. 4, FIG. 24A). 33% and 50%iPrSi-doped samples exhibit Tg values closer to or below roomtemperature (46° C. and 14° C., respectively), which accounts for theirlower moduli as measured by tensile testing at room temperature. Insupport of this notion, all of the samples displayed similar moduli atTg—60° C. as measured by DMA (FIG. 24B).

Outstanding ballistic impact resistance is one of the most well-knownproperties of pDCPD.²⁸ To assess the ballistic impact response of ourdegradable analogues, laser induced projectile impact tests (LIPIT) wereconducted on 10% iPrSi-doped and native pDCPD films (23.0±1.7 μm) usingsteel microparticles (12.8±0.4 μm diameter).²⁹ High-speed imagingrevealed that films of 10% iPrSi-doped material stopped projectiles withthe same efficiency as native pDCPD (FIG. 19F, FIGS. 61-63, Tables 3 and4).

TABLE 3 LIPIT Data for 0% iPrSi−doped pDCPD. Post- Impact ImpactCoefficient Particle Film Velocity Velocity of Diameter Thickness m/sUncertainty m/s Uncertainty Restitution Uncertainty (μm) (μm) 718 14.360 0 0 0 13.2 21.75 820 16.4 154 3.08 0.187805 0.005312 12.5 22.5 67513.5 0 0 0 0 12.5 23.25 895 17.9 310 6.2 0.346369 0.009797 12.2 23.25851 17.02 342 6.84 0.40188 0.011367 12.7 22.75 949 18.98 512 10.240.539515 0.01526 12.2 22.75 841 16.82 291 5.82 0.346017 0.009787 12.922.5 606 12.12 0 0 0 0 12.3 21 910 18.2 530 10.6 0.582418 0.016473 12.722.5 855 17.1 322 6.44 0.376608 0.010652 11.8 24.75 691 13.82 0 0 0 012.7 24 593 11.88 0 0 0 0 12.9 24 155 3.1 −61 −1.22 −0.39355 −0.0111312.8 25.5 488 9.76 −38 −0.76 −0.07787 −0.0022 13.2 27 572 11.44 0 0 0 013.2 24.75 567 11.34 0 0 0 0 13.1 24.75 376 7.52 −51.7 −1.034 −0.1375−0.00389 13.2 24.75 328 6.56 −63 −1.26 −0.19207 −0.00543 13.6 24.75 4308.6 0 0 0 0 13.9 21 255 5.1 −79 −1.58 −0.3098 −0.00876 13.4 23.25 2615.22 −67 −1.34 −0.2567 −0.00726 13.2 24.75 300 6 −81 −1.62 −0.27−0.00764 12.5 24.75 395 7.9 −56 −1.12 −0.14177 −0.00401 13.3 23.25 3076.14 −73 −1.46 −0.23779 −0.00673 12.9 23.25 443 8.86 −70 −1.4 −0.15801−0.00447 12.5 23.25 469 9.38 −37 −0.74 −0.07889 −0.00223 12.8 23.25

TABLE 4 LIPIT Data for 10% iPrSi-doped pDCPD. Post- Impact ImpactCoefficient Partticle Film Velocity Velocity of Diameter Thickness m/sUncertainty m/s Uncertainty Restitution Uncertainty (μm) (μm) 656 13.120 0 0 0 12.9 20.25 677 13.54 0 0 0 0 12.2 22.5 149 2.98 −61 −1.220.409396 0.011579 12.5 23.5 235 4.7 −75 −1.5 0.319149 0.009027 12.9 23.5243 4.86 −77 −1.54 0.316872 0.008963 12.5 23.5 364 7.28 −78 −1.560.214286 0.006061 11.8 24.05 507 10.14 0 0 0 0 12.9 24.05 537 10.74 0 00 0 12.9 24.05 433 8.66 0 0 0 0 12.9 24 427 8.54 −58 −1.16 0.1358310.003842 12.5 23.5 344 6.88 −75 −1.5 0.218023 0.006167 12.6 24.5 2895.78 −77 −1.54 0.266436 0.007536 12.4 25.5 879 17.58 367 7.34 −0.41752−0.01181 12.2 18 936 18.72 492 9.84 −0.52564 −0.01487 13.0 21 936 18.72504 10.08 −0.53846 −0.01523 13.1 21 898 17.96 461 9.22 −0.51336 −0.0145212.9 21 880 17.6 422 8.44 −0.47955 −0.01356 12.5 21 718 14.36 42 0.84−0.0585 −0.00165 12.7 21 726 14.52 0 0 0 0 12.9 21 725 14.5 0 0 0 0 12.222 570 11.4 0 0 0 0 12.7 21 829 16.58 375 7.5 −0.45235 −0.01279 13.3 21739 14.78 219 4.38 −0.29635 −0.00838 13.2 21 781 15.62 266 5.32 −0.34059−0.00963 12.3 24 661 13.22 0 0 0 0 13.1 24 615 12.3 0 0 0 0 13.0 24

The coefficient of restitution (CoR), defined as the ratio of reboundvelocity to impact velocity, was similar for these materials acrossimpact velocity regimes of particle rebound, embedment, and filmperforation (FIG. 19G), indicating indistinguishable high strain-rateresponses.

Next, the degradation of these materials was probed in more detail. Inaddition to TBAF, which is convenient for laboratory scale reactions,hydrofluoric acid, which is used to etch silicon on large scale in thesemiconductor industry, readily dissolved our iPrSi doped pDCPD at roomtemperature (FIG. 41). Silyl ethers are also susceptible to cleavageunder acidic or basic conditions³⁰; however, due to their hydrophobicnature, iPrSi-doped pDCPD samples displayed sluggish hydrolysis inaqueous acidic (pH=0) or basic (pH=14) conditions, though they did showevidence of surface etching following exposure to aqueous sodiumhydroxide for 30 minutes (FIG. 42). To demonstrate tuning thedegradation of these materials, we prepared samples doped with 10% v/vof EtSi, a comonomer significantly more susceptible to hydrolysis.¹⁷These materials displayed enhanced degradation under mixedaqueous/organic acidic conditions (FIGS. 25A-25D). Through the use of awider range of comonomers, it may be possible to generate thermosetswith variable degradation rates and mechanisms (e.g., photochemical,enzymatic, etc.).³¹

Finally, given concerns over the accidental release of plastic wasteinto the natural environment,³² degradation of iPrSi- and EtSi-dopedpDCPD exposed to synthetic seawater and ultraviolet light for 16 dayswas studied (FIG. 2B, FIG. 7A, FIGS. 26A-26B). Significant increases (upto ˜2-3 fold) in the extent of degradation relative to native pDCPD wereobserved. Transmission electron microscopy (TEM) revealed the presenceof sub-5-nm particles following degradation (FIG. 43). While thegeneration of microplastics (typically micrometre-millimetre-rangeparticles) may be a concern,³³ nanoscale plastics could be importantintermediates that enhance the total degradation rate of bulk plastics.Notably, optimization of the size and composition of pDCPD degradationproducts can be achieved by tuning the silyl ether monomer substituentsand loading, which is challenging for less selective degradationprocesses.

Characterization of iPrSi-Doped pDCIPD Degradation Products andReprocessing

The degradation products of iPrSi-doped pDCPD are hydroxylated polymersbearing cyclopentene functionalities that could be used for recycling orrepurposing (FIG. 3C). To demonstrate this concept, samples of 10, 20,33, or 50% iPrSi-doped pDCPD were prepared and subjected to degradationusing TBAF (FIG. 44). The resulting soluble products were characterizedby 1-D and 2-D solution-state NMR, including ¹H, ¹³C, COSY, HSQC, HMBC,and NOESY (FIGS. 45-50) with greatly improved resolution compared tosolid-state NMR (FIG. 3B). To enable comparison of the NMR spectra, asample of linear, non-crosslinked pDCPD was independently prepared(FIGS. 51-52).³⁴ From the combination of these studies, a 3:2 ratio ofaliphatic to olefin carbons could be assigned in the ¹³C NMR spectrum ofthe iPrSi-doped pDCPD degradation products, indicating that ˜15% of thecyclopentenes of the polynorbornene strands had reacted (FIG. 3B). Basedon our model (FIG. 17B), a material with 15% effective crosslinks wouldrequire >15% cleavable bonds to degrade into soluble products; thus, itwas estimated that a large fraction of the reacted cyclopentene groupsin pDCPD are consumed through intramolecular reactions (loops). Thisinsight into the structure of pDCPD, uniquely enabled by the cleavablecomonomer approach, lends clear and quantitative support to the model ofpDCPD as being crosslinked by secondary metathesis reactions ofcyclopentene substituents.³⁵

To examine the role of iPrSi loading on degradation product size, thesoluble samples prepared above were analyzed by gel permeationchromatography (GPC) (FIG. 20A) and diffusion ordered spectroscopy(DOSY) (FIGS. 53-56), both of which showed an inverse relationshipbetween iPrSi loading and degradation product size. From GPC, theweight-average molar masses of these samples ranged from 2-8 kDa (Table5), while DOSY was used to estimate that the average diameter of thedegradation products of the 10% iPrSi-doped material was ˜4 nm, which ison the length scale of individual polymer strands. This result wasfurther corroborated by TEM imaging (FIG. 3D).

TABLE 5 Calculated Fragment Molecular Weights from GPC-MALS Sample M_(w)M_(n) M_(w)/M_(n) 10% iPrSi 7.70 × 10³ 3.41 × 10³ 2.26 20% iPrSi 5.72 ×10³ 2.13 × 10³ 2.69 33% iPrSi 3.19 × 10³ 1.95 × 10³ 1.63 50% iPrSi 1.91× 10³ 1.38 × 10³ 1.38

Given that these degradation products possess many unreactedcyclopentene substituents (FIGS. 3B-3C), it was reasoned that they couldbe reprocessed into new pDCPD materials. Indeed, mixing the degradationproducts of our 10% iPrSi-doped material (25 wt. %) with DCPD and curingfollowing the same procedure used for native pDCPD produced recycledsamples with comparable stress-strain behavior and elastic moduli (FIGS.20B-20C, FIGS. 20B, 57). Moreover, the recycled samples displayedsimilar ballistic impact resistance to native pDCPD. Finally, carbonfiber composites of pDCPD have been explored for high-performanceapplications,¹⁶ but the costly embedded carbon fiber typically cannot berecovered from such materials. When carbon fiber fabrics were embeddedinto 10% iPrSi-doped pDCPD, they could be quantitatively recovered (FIG.20F). Raman spectra for pristine versus recovered carbon fiber were verysimilar, suggesting that the mild pDCPD degradation process has noimpact on the fiber composition. These results hint at potentialopportunities for thermoset composite recycling.

Methods A General Theoretical Framework for Degradable Thermosets ViaCopolymerization

The theoretical model for network degradation is described herein infurther detail. The following variables were used, which are consistentwith the terminology defined in FIGS. 17A-17D. Moreover, an additionalvariable was introduced for the dispersity of the degradation fragments.f=number-average degrees of polymerization of non-degradable, functional(crosslinkable) monomer (e.g, DCPD) c=number-average crosslinks perstrand (i.e., the number off groups that have reacted to formcrosslinks) x=number-average degrees of polymerization of degradablecomonomer (e.g., iPrSi) D=dispersity of linear fragments obtained afterstrand degradation in reverse gel-point model.

To begin, it was assumed that the network structure formed by thecrosslinking of linear copolymer strands followed by cleavage ofdegradable bonds in those strands was identical to the network formed byfirst cleaving the linear copolymer strands and then cross-linking theresulting “fragments” as shown in FIGS. 21A-21B. Then, classicalFlory-Stockmayer and Miller-Macosko theories were leveraged to determinewhat values of x would inhibit gelation for given values off and c. Asis the case for these classical gelation theories, the model assumesthat all functional groups of the same type have equal reactivity, thatall functional groups react independently of each other, and that thereare no intramolecular reactions. Moreover, it was assumed thatdegradable comonomers x are randomly distributed along the strandbackbone.

The number-average degrees of polymerization (DP) of the linearfragments generated after degradable monomer cleavage was estimated as:

$\begin{matrix}{{DP} = \frac{f}{x + 1}} & (1)\end{matrix}$

To provide an estimate of D for these fragments, a Monte Carlo analysiswas applied where x degradable co-monomers were randomly incorporatedinto a linear polymer of DP=f and calculated the fragment DP afterdegradation. This process was repeated 10⁶ times to arrive, as expectedwhen f>>x>>1,³⁶ a fragment dispersity of ˜2.

Based on Miller-Macosko theory, the critical extent of reaction requiredfor gelation during crosslinking a disperse mixture of polymer strandswith a single cross-linking functionality was defined as p_(c):

$\begin{matrix}{p_{c} = \frac{1}{f_{w} - 1}} & (2)\end{matrix}$

where f_(w) is the weight-average crosslink functionality of thefragments, which was defined as:

$\begin{matrix}{f_{w} = \frac{Ðf}{x + 1}} & (3)\end{matrix}$

it was also noted that for crosslinked networks below the gel point:

$\begin{matrix}{\frac{c}{f} < p_{c}} & (4)\end{matrix}$

Combining equations (2) and (4), the following was obtained:

$\begin{matrix}{\frac{c}{f} < \frac{1}{( \frac{Ðf}{( {x + 1} )} ) - 1}} & (5)\end{matrix}$

Solving for x provides the following relationship

$\begin{matrix}{x > \frac{{c( {{Ðf} - 1} )} - f}{c + f}} & (6)\end{matrix}$

Assuming D=2 arrives at the expression provided in the main text andplotted in FIG. 17B for f=3000:

$\begin{matrix}{x > \frac{{c( {{2f} - 1} )} - f}{c + f}} & (7)\end{matrix}$

While the model can account for any f or c value, in practice, manymaterials can be approximated by either of two limiting cases: f>>c orf˜c. The limiting case of f>>c reflects materials where the number ofcrosslinks is low relative to the number of potential crosslinkablefunctionalities. Such is the case for vulcanized thermosets. Incontrast, the limiting case of f˜c corresponds to materials where nearlyevery crosslinkable functionality is involved in a crosslink, as isfound, for example, in many epoxy thermosets.

pDCPD Resin Precursor Preparation

Dicyclopentadiene (DCPD) and iPrSi were mixed in the desired ratio.Next, finely powdered Grubbs 2^(nd) generation ROMP initiator wasdissolved into this mixture at a concentration of 2 mg/mL. The finelypowdered initiator was generated by dissolving the commercially obtainedGrubbs 2^(nd) generation complex in dichloromethane in a glass vial,evaporation of the solvent under vacuum, and scraping the residue fromthe side of the vial with a spatula. This process enabled the rapid andfull dissolution of the catalyst in DCPD/iPrSi mixtures. The solutionsremained liquid at room temperature at silyl ether concentrations of 10%or higher, while solidification occurred at 5% or lower concentrations.In these cases, the solidified monomer mixture was melted by gentleheating in a water bath (˜40° C.). The homogenous pink solutions wereused within 5 min to prepare resins of the desired geometry. pDCPD ResinSynthesis (Pellets) 200 μL of the solutions described above were addedto 2 mL flat-bottom screw thread glass vials (VWR, Part No. 46610-772,12×32 mm). The vials were heated to 120° C. for 15 min in an oven,during which time the pink solution turned into a yellow solid as itpolymerized and crosslinked to form pDCPD. The vials were then removedfrom the oven, cooled to room temperature, and broken with a hammer torelease the sample. The collected pDCPD samples were cured for another30 minutes at 120° C. and then stored at room temperature until furtheruse.

Laser-Induced Projectile Impact Testing of iPrSi-Doped pDCPD

Laser induced projectile impact testing (LIPIT) served as a platform forstudying the high strain-rate impact response of materials²⁹. LIPIT hasbeen utilized previously to study the impact responses of gels, metals,ceramics, and a range of other materials^(29,37-40). In brief, ahigh-energy laser pulse (Nd:YAG, 532 nm, 10 ns) was focused onto a glasssubstrate (210 μm) coated with an ablative gold layer (60 nm), and apolyurea film (40 μm)—this glass-gold-polyurea configuration willhereafter be referred to as the “launch pad”. The launch pad was coatedwith microparticles and after ablation of the gold layer by ahigh-energy laser pulse, a particle was propelled at high speeds rangingfrom tens of m/s up to 2 km/s, with the characteristic strain-ratedefined as the impact velocity divided by particle diameter. Theprojectile speed was varied by adjusting the laser pulse energy.Particle trajectory and impact were captured via an ultra-high-speedcamera (SIMX16, Specialized Imaging) with 16 independently triggeredCCDs, illuminated by a second pulsed laser (640 nm, 30 μs). Thisprovided 16 frames with a minimum exposure time of 5 ns and variedinterframe time. The particle pre-impact velocity (ν_(i)) andpost-impact velocity (ν_(r)) were extracted from the image sequences.All particle diameters were measured prior to impact, and filmthicknesses were measured with confocal microscopy after impact.

In this experiment, steel microparticles (12.8±0.4 μm diameter) werelaunched with speeds ranging between 150±3 and 950±19 m/s at filmsamples with thicknesses of 23.0±1.7 μm. Three regimes of impactresponse were observed: particle rebound, particle embedment, and filmperforation. The coefficient of restitution (CoR), the ratio of pre- andpost-impact velocities (−ν_(r)/ν_(i)), was calculated and plotted tocompare the impact responses of the two films. Positive, zero, andnegative CoR correspond to particle rebound, embedment and filmperforation respectively.

Weathering Experiments

To assess pDCPD degradability under the marine environment, the materialwas exposed to a synthetic seawater matrix both in the dark and undersimulated solar irradiation. It was hypothesized that photooxidation ofiPrSi-doped pDCPD would further enhance its aqueous wettability byintroducing oxygen functional groups, assisting the hydrolysis of silylether groups. An approximately 100 mg polymer pellet was submerged inthe bottom of 60 mL of synthetic seawater matrix in a clear vial sealedwith PTFE-lined cap. The synthetic seawater recipe was: 420 mM NaCl, 0.8mM NaBr, 29 mM Na₂S04, 54 mM MgCl₂.6H₂O, 11 mM CaCl₂.2H₂O, 10 mM KCl,0.35 mM H₃BO₃, 1.8 mM NaHCO₃, and 0.26 mM Na₂CO₃, 5 nM FeCl₃ ⁴¹.

The vial was then exposed placed within a Rayonet photoreactor with Hglamps and an output spectrum shown in FIG. 7A and FIG. 26A (measured byOceanInsight FLAME-S-XR1-ES spectroradiometer) for 16 days. Glasscontainers were used to filter sub-300-nm light to more closely emulatethe solar distribution (represented by ASTM 177 reference spectra). Thetemperature was controlled in both the light and dark experiments to45-46° C., where the temperature inside the Rayonet reactor wasmonitored and the dark experiments were kept in an oven maintained at45-46° C.

Degradation was calculated as the mass of carbon released in theseawater solution over the mass of carbon in the original material.Total organic carbon was measured as non-purgable organic carbon by aShimazu TOC-5000. Prior to analysis, the sample was acidified with 50%HCl to pH<3 and sparged with N₂ for 8 min to remove inorganic carbon inseawater matrix. Total organic carbon in the virgin polymer was inferredfrom the chemical formulas and mass fractions of iPrSi or EtSico-monomers. A paired t-Test was performed to determine whether contentof iPrSi or light exposure has an impact on degradability.

Recycling of pDCPD Fragments

pDCPD fragments derived from 10% iPrSi-doped pDCPD were preparedfollowing the standard workflow described above. 500 mg of the fragmentswere then dissolved in 1.5 g of DCPD, forming a viscous brown liquid. Tothis liquid was added 8 mg of finely powdered Grubbs' 2^(nd)generationROMP initiator. The material was poured into vials (for forming discs)and silicone molds (for tensile and DMA measurements) and cured at 120°C. for 30 min.

Comparison of EtSi vs. iPrSi-Doped pDCPD

10% EtSi doped pDCPD was prepared in an analogous manner to that ofiPrSi doped pDCPD to generate ˜200 mg pellets. For dissolutionexperiments, the material was placed into a 20 mL vial and 10 mL of 15%conc. HCl in THF or 0.5 M TBAF were added. The resulting mixtures werethen monitored over time.

Dissolution of iPrSi-Doped pDCPD with HF-Pyridine Complex

A ˜200 mg pellet of 10% iPrSi-doped pDCPD was covered with 2 mL of THFin a 15 mL Falcon tube. Next, 20 μL of HF-pyridine complex was added.The material was allowed to incubate for 24 hours, upon which time thebulk of the material had entirely dissolved.

Techno-Economic Analysis

A systematic search of several synthetic pathways was performed toidentify existing literature precedents for transformations performed onscale. Calculations used to calculate the prices for each reagent areshown below:

Calculations for Feedstock Contribution to Price of iPrSi

Isopropylchloride (IPC)

$\lbrack {{( \frac{{\$ 1}{.00}}{1\mspace{14mu} {kg}\mspace{14mu} {{Prop}.}} )( \frac{42.08\mspace{14mu} {kg}}{1\mspace{14mu} {kmol}\mspace{14mu} {{Prop}.}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {{Prop}.}}{0.94{\mspace{11mu} \;}{kmol}\mspace{14mu} {IPC}} )} + {( \frac{{\$ 0}{.50}}{1\mspace{14mu} {kg}\mspace{14mu} {HCl}} )( \frac{36.46\mspace{14mu} {kg}}{1\mspace{14mu} {kmol}\mspace{14mu} {HCl}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {HCl}}{0.94{\mspace{11mu} \;}{kmol}\mspace{14mu} {IPC}} )}} \rbrack = {\frac{{\$ 64}{.16}}{1\mspace{14mu} {kmol}\mspace{14mu} {IPC}}\mspace{14mu} {or}\mspace{14mu} \frac{{\$ 0}{.82}}{1\mspace{14mu} {kg}\mspace{14mu} {IPC}}}$

iPr₂SiCl₂

$\lbrack {{( \frac{{\$ 64}{.16}}{1\mspace{14mu} {kmol}\mspace{14mu} {IPC}} )( \frac{2\mspace{14mu} {kmol}\mspace{14mu} {IPC}}{1\mspace{14mu} {kmol}\mspace{14mu} {iPr}_{2}{{SiCl}_{2}.}} )} + {( \frac{{\$ 2}{.65}}{1\mspace{14mu} {kg}\mspace{14mu} {Silicon}} )( \frac{28.09\mspace{14mu} {kg}}{1{\mspace{11mu} \;}{kmol}\mspace{14mu} {Silicon}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {Silicon}}{1\mspace{14mu} {kmol}\mspace{14mu} {iPr}_{2}{SiCl}_{2}} )}} \rbrack = {\frac{{\$ 202}{.76}}{1\mspace{14mu} {kmol}{\mspace{11mu} \;}{iPr}_{2}{SiCl}_{2}}\mspace{14mu} {or}\mspace{14mu} \frac{{\$ 1}{.10}}{1\mspace{14mu} {kg}\mspace{14mu} {iPr}_{2}{SiCl}_{2}}}$

3-Butene-1-ol (3B10)

$\lbrack {{( \frac{{\$ 1}{.00}}{1\mspace{14mu} {kg}\mspace{14mu} {{Prop}.}} )( \frac{42.08\mspace{14mu} {kg}}{1\mspace{14mu} {kmol}\mspace{14mu} {{Prop}.}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {{Prop}.}}{0.88\mspace{20mu} {kmol}\mspace{14mu} 3{B1O}} )} + {( \frac{{\$ 1}{.08}}{1\mspace{14mu} {kg}\mspace{14mu} {CH}_{2}O} )( \frac{30.03\mspace{14mu} {kg}}{1\mspace{14mu} {kmol}\mspace{14mu} {CH}_{2}O} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {CH}_{2}O}{0.88{\mspace{11mu} \;}{kmol}\mspace{14mu} 3{B1O}} )}} \rbrack = {\frac{{\$ 84}{.67}}{1\mspace{14mu} {kmol}\mspace{14mu} 3{B1O}}\mspace{14mu} {or}\mspace{14mu} \frac{{\$ 1}{.17}}{1\mspace{14mu} {kg}\mspace{14mu} 3{B1O}}}$

2-pentene-1,5-diol (PDO)

$\lbrack {{( \frac{{\$ 84}{.67}}{1\mspace{14mu} {kmol}\mspace{14mu} 3{B1O}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} 3{B1O}}{0.45\mspace{14mu} {kmol}\mspace{14mu} {PDO}} )} + {( \frac{{\$ 1}{.08}}{1\mspace{14mu} {kg}\mspace{14mu} {CH}_{2}O} )( \frac{30.03\mspace{14mu} {kg}}{1{\mspace{11mu} \;}{kmol}\mspace{14mu} {CH}_{2}O} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {CH}_{2}O}{0.45\mspace{14mu} {kmol}\mspace{14mu} {PDO}} )}} \rbrack = {\frac{{\$ 260}{.23}}{1\mspace{14mu} {kmol}{\mspace{11mu} \;}{PDO}}\mspace{14mu} {or}\mspace{14mu} \frac{{\$ 2}{.55}}{1\mspace{14mu} {kg}\mspace{14mu} {PDO}}}$

iPrSi

$\lbrack {{( \frac{{\$ 260}{.23}}{1\mspace{14mu} {kmol}\mspace{14mu} {PDO}} )( \frac{1\mspace{14mu} {kmol}\mspace{14mu} {PDO}}{0.5\mspace{14mu} {kmol}\mspace{14mu} {iPrSi}} )} + {( \frac{{\$ 202}{.76}}{1\mspace{14mu} {kmol}\mspace{14mu} {iPr}_{2}{SiCl}_{2}} )( \frac{1\mspace{14mu} {kmol}{\mspace{11mu} \;}{iPr}_{2}{SiCl}_{2}}{0.5\mspace{14mu} {kmol}\mspace{14mu} {iPrSi}} )}} \rbrack = {\frac{{\$ 925}{.98}}{1\mspace{14mu} {kmol}\mspace{14mu} {iPrSi}}\mspace{14mu} {or}\mspace{14mu} \frac{{\$ 4}{.32}}{1\mspace{14mu} {kg}\mspace{14mu} {iPrSi}}}$

TEM Characterization of Organic Material Released During Weathering

To characterize the organic material released into solution duringweathering, approximately 10 mL of post-irradiation sample was extractedwith 5 mL DCM. 2 mL of the organic layer was then collected and thesolvent removed. The remaining organic residue was dissolved in 200 μLof DCM. 5 μL of sample was cast onto a TEM grid. The samples were thenstained with RuO4 vapor for 5 minutes and imaged by TEM on an FEI Tecnaitransmission electron microscope (FIG. 43).

Crosslink Quanification from ¹³C NMR

We assigned the peak at 55 ppm to the allylic carbon of the ring-closedDCPD monomer (red circle, C4). Upon ring opening, the chemical shift ofthis peak moves upfield to resemble more closely the two bridgeheadnorbornene carbons (blue circles, C2/C5). HSQC allowed for theassignment of the peaks from 35-40 ppm to the norbornene methylene(yellow circle, C7) and the peaks at 35 ppm to the allylic cyclopentenecarbon (green circle, C8). We found that the integral under the 55 ppmC4 peak was lower than expected (only 85%) when compared to theintegrations for C7 or C8, suggesting 15% of the cyclopentenes werering-opened. ¹³C measurements for integration were acquired on a BrukerNeo 500 in CDCl₃. A total of 2048 scans (300 ms delay time, 1 s overallrecycle time, 30-45 degree acquisition pulse) were used for acquisition.Peak integration was performed using MestreNova. As none of the carbonsare quaternary, we assume that these acquisition parameters aresufficient to provide accurate integration values in our analysis. Toconfirm the suitability of these parameters, we performed an additionalmeasurement using a 10 s overall recycle time, which provided identicalrelative integrations for the peaks under analysis.

Recovery of Carbon Fiber from pDCPD Composites

Twill-weave carbon fiber (McMaster Carr) was mounted on a piece of tapeand cut into a 15×15 mm square. The tape was placed into a 20 mL vialand covered with 1 mL of 10/iPrSi-doped DCPD precursor (with Grubbs'catalyst, 2 mg/mL). The material was then cured at 120° C. for 30minutes and the sample removed from the vial. The sample was then placedinto a glass chamber and covered with 5 mL of 0.2 M TBAF. After 8 hours,the carbon fiber was carefully removed from the chamber and allowed todry overnight. Some fraying of the material was observed, which isattributed to loss of the tape used to mount the material over thecourse of composite synthesis and TBAF dissolution.

Raman Spectroscopy Characterization of Recovered Carbon Fiber

Raman spectra were collected using a Horiba Jobin-Yvon LabRam (Model HR800) Raman confocal microscope with a 532 nm laser (1.2 μm spot size)excitation and an acquisition time of 3 seconds. Laser intensity was setto 25% for the 532 nm excitation wavelength. Raman spectra werenormalized to the G-band (˜1590 cm⁻¹) and averaged from three individualspectra recorded at different locations on the sample surface.

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Cyclic Olefin Monomers for Backbone Degradable ROMP Copolymers

Described herein are a class of low molecular weight cyclic olefinmonomers that copolymerize efficiently with norbornenes. When mixed withnorbornene monomers before polymerization, the resulting polymers areshown to degrade under aqueous acidic conditions. The low molecularweight of these monomers and their ease of preparation opens the door tomany opportunities for backbone degradable materials.

Silyl ether monomers that copolymerized efficiently with norbornenes togenerate backbone degradable ROMP polymers were previously disclosed.These monomers, however, were prepared through expensive silyl chlorideintermediates. In contrast, other types of cyclic olefin monomers thatcan be prepared readily from inexpensive reagents and on scale wouldovercome this limitation. Ultimately, this design feature—cyclicmonomers that contain an endo-cyclic cleavable bonds—copolymerize withnorbornenes, provide a general solution to endow degradability to allnorbornene-based polymeric materials prepared by ROMP.

Synthetic Protocols

1.02 g (10 mmol) of diol and 1.09 mL of trimethyl orthoformate wereadded to a flask. Next, 0.126 g of PPTS was added and the mixture wasstirred for 30 minutes. The solution was then concentrated to yield awaxy solid. Then, 0.741 mL (1 equivalent) of dry acetone was added andthe reaction was stirred for 24 hours. The mixture was then distilledunder vacuum to yield acetal 1 as a clear oil. (0.587 g).

1.02 g (10 mmol) of diol and 1.09 mL of trimethyl orthoformate wereadded to a flask. Next, 0.126 g of PPTS was added and the mixture wasstirred for 30 minutes. The solution was then concentrated to yield awaxy solid. Then, 0.912 mL (1 equivalent) of isobutyraldehyde was addedand the reaction was stirred for 24 hours. The mixture was thendistilled under vacuum to yield acetal 2 as a clear oil. (0.99 g).

Synthesis of iPrAc-7 and iPrAc

2.64 g of (Z)-2-butene-1,4-diol, 3.18 g of trimethylorthoformate, and376 mg of pyridinium para-toluene sulfonate were combined in a vial andstirred for 30 minutes. The material was then concentrated under gentlevacuum to yield a viscous oil. Next, 2.16 g of isobutyraldehyde wasadded and the material was stirred overnight. The residual liquid wasconcentrated under gentle vacuum and further distilled to yield crudeiPrAc-7

as a clear oil. The material was passed through a plug of silica withhexanes to yield 1.7 g of iPrAc-7 as a clear oil.

1.01 g of (Z)-pent-2-ene-1,5-diol, 1.06 g of trimethylorthoformate, and126 mg of pyridinium para-toluene sulfonate were combined in a vial andstirred for 30 minutes. The material was then concentrated under gentlevacuum to yield a viscous oil. Next, 720 mg of isobutyraldehyde wasadded and the material was stirred overnight. The residual liquid wasconcentrated under gentle vacuum and further distilled to yield crudeiPrAc

as a clear oil. The material was passed through a plug of silica withhexanes to yield 550 mg of iPrAc as a clear oil.Copolymerization of iPrAc and iPrAc-7 with PEG-Macromonomers

Bottlebrush polymers were synthesized using 200 mg of PEG-macromonomers(PEG-MM) in 800 μL of dioxane. 200 μL of solution were added into eachof four one-dram vials, followed by 30 μL of 0.5 M comonomer in dioxaneor 30 μL of dioxane. Finally, 75 μL of 0.02 M Grubbs' 3rd generationcatalyst in dioxane were added to target a DP of 10 for each monomer.The mixture was stirred for 30 min, quenched with a drop of EVE, andanalyzed by GPC.

To force degradation of the material, the polymerization solution wasconcentrated in a vacuum chamber at room temperature to remove residualEVE and diluted in 100 μL of dioxane. To the solution were added 10 μLof 2M HCl. The mixture was stirred for 30 minutes. Excess sodium sulfatewas added and the mixture was allowed to sit for 5 min. Finally, themixture was extracted with DCM, filtered with a 0.2 μm nylon filter,concentrated, and analyzed by GPC.

Synthesis and Degradation of iPrAc/iPrAc-7 Doped pDCPD

25, 50, 75, and 100 μL of iPrAc/iPrAc-7 were combined with 975, 950,925, or 900 μL of DCPD, respectively. The combined monomers were addedto 2 mg of finely powdered Grubbs' 2^(nd) generation catalyst. 150 μLaliquots of material were added to glass vials and cured at 120° C. for30 minutes.

The samples were removed from the vial, dissolved in 3 mL of THF with10% v/v 2 M HCl in Et₂O and incubated for 1-12 hours. After 1 hour,pDCPD containing 7.5% or 10% v/v iPrAc had dissolved (where as thecorresponding iPrAc-7 samples did not). For a 10% iPrAc sample, thesoluble material was collected, diluted with 10 mL fresh THF, andbasicified by stirring with solid CaCO₃ for 30 minutes. The solvent wasthen removed under vacuum. The material was dissolved in choloroform,concentrated, and analyzed by NMR.

Sample Preparation of pDCPD Containing DHF

135 μL of DCPD was added to 15 μL of DHF

The mixture was added to a vial containing 2 mg/mL of finely powderedGrubbs' 2^(nd) generation catalyst. The resulting mixture was added inits entirety to a glass vial, left at room temperature for 2 hours toform a high boiling point pre-polymer, then heated at 120° C. for 30minutes to cure. The vials were then broken to release the samples.

Samples were incubated in 1 mL of THF with 2 equivalents of HCl (2M inwater) relative to DHF for 24 hours. The soluble fragments werecarefully removed by pipette and the residual solids were resuspended infresh THF. The fragments were redissolved in chloroform, concentrated,and characterized by NMR.

EQUIVALENTS AND SCOPE

In the claims articles such as “a,” “an,” and “the” may mean one or morethan one unless indicated to the contrary or otherwise evident from thecontext. Claims or descriptions that include “or” between one or moremembers of a group are considered satisfied if one, more than one, orall of the group members are present in, employed in, or otherwiserelevant to a given product or process unless indicated to the contraryor otherwise evident from the context. The invention includesembodiments in which exactly one member of the group is present in,employed in, or otherwise relevant to a given product or process. Theinvention includes embodiments in which more than one, or all of thegroup members are present in, employed in, or otherwise relevant to agiven product or process.

Furthermore, the invention encompasses all variations, combinations, andpermutations in which one or more limitations, elements, clauses, anddescriptive terms from one or more of the listed claims is introducedinto another claim. For example, any claim that is dependent on anotherclaim can be modified to include one or more limitations found in anyother claim that is dependent on the same base claim. Where elements arepresented as lists, e.g., in Markush group format, each subgroup of theelements is also disclosed, and any element(s) can be removed from thegroup. It should it be understood that, in general, where the invention,or aspects of the invention, is/are referred to as comprising particularelements and/or features, certain embodiments of the invention oraspects of the invention consist, or consist essentially of, suchelements and/or features. For purposes of simplicity, those embodimentshave not been specifically set forth in haec verba herein. It is alsonoted that the terms “comprising” and “containing” are intended to beopen and permits the inclusion of additional elements or steps. Whereranges are given, endpoints are included. Furthermore, unless otherwiseindicated or otherwise evident from the context and understanding of oneof ordinary skill in the art, values that are expressed as ranges canassume any specific value or sub-range within the stated ranges indifferent embodiments of the invention, to the tenth of the unit of thelower limit of the range, unless the context clearly dictates otherwise.

This application refers to various issued patents, published patentapplications, journal articles, and other publications, all of which areincorporated herein by reference. If there is a conflict between any ofthe incorporated references and the instant specification, thespecification shall control. In addition, any particular embodiment ofthe present invention that falls within the prior art may be explicitlyexcluded from any one or more of the claims. Because such embodimentsare deemed to be known to one of ordinary skill in the art, they may beexcluded even if the exclusion is not set forth explicitly herein. Anyparticular embodiment of the invention can be excluded from any claim,for any reason, whether or not related to the existence of prior art.

Those skilled in the art will recognize or be able to ascertain using nomore than routine experimentation many equivalents to the specificembodiments described herein. The scope of the present embodimentsdescribed herein is not intended to be limited to the above Description,but rather is as set forth in the appended claims. Those of ordinaryskill in the art will appreciate that various changes and modificationsto this description may be made without departing from the spirit orscope of the present invention, as defined in the following claims.

1. A functional oligomer or functional polymer comprising: i) one ormore instances of linear units, wherein each instance of the linearunits is of the formula:

ii) one or more instances of functional units, wherein each instance ofthe functional units is independently of the formula:

iii) optionally one or more instances of crosslinking units, whereineach instance of the crosslinking units is of the formula:

and iv) optionally one or more additional linear units, one or moreadditional terminal units, and/or one or more additional crosslinkingunits; wherein: each instance of Z is independently a single bond,C(R^(P))₂, or O; each instance of R^(P) is independently hydrogen,halogen, or substituted or unsubstituted, C₁₋₆ alkyl; each instance of

is independently a single or double bond; each instance of R^(H) isindependently hydrogen, halogen, substituted or unsubstituted alkyl,substituted or unsubstituted alkenyl, substituted or unsubstitutedalkynyl, substituted or unsubstituted carbocyclyl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted aryl,substituted or unsubstituted heteroaryl, —OR^(a), —OCN, —OC(═O)R^(a),—OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂, —OS(═O)R^(a),—OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a), —OS(═O)₂OR^(a),—OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)),—OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo, —N(R^(a))₂, N═C(R^(a))₂,═NR^(a), —NC, —NCO, —N₃, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a),—NR^(a)C(═O)N(R^(a))₂, —NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR^(a),—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),—NR^(a)S(═O)₂N(R^(a))₂, —SR^(a), —SCN, —S(═O)R^(a), —S(═O)OR^(a),—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂,—SeR^(a), halogen, —CN, —C(═NR^(a))R^(a), —C(═NR^(a))OR^(a),—C(═NR^(a))N(R^(a))₂, —C(═O)R^(a), —C(═O)OR^(a), —C(═O)SR^(a),—C(═S)OR^(a), or —C(═O)N(R^(a))₂; or the two instances of R^(H) of oneor more instances of

are joined with the intervening carbon atoms to independently form asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring; each instance of R^(a) is independentlyhydrogen, substituted or unsubstituted alkyl, substituted orunsubstituted alkenyl, substituted or unsubstituted alkynyl, substitutedor unsubstituted, monocyclic carbocyclyl, substituted or unsubstituted,monocyclic heterocyclyl, substituted or unsubstituted, monocyclic aryl,substituted or unsubstituted, monocyclic heteroaryl, a nitrogenprotecting group when attached to a nitrogen atom, an oxygen protectinggroup when attached to an oxygen atom, or a sulfur protecting group whenattached to a sulfur atom, or two instances of R^(a) are joined to formsubstituted or unsubstituted heterocyclyl or substituted orunsubstituted heteroaryl; each instance of R^(J) is independently—OR^(a), —OCN, —OC(═O)R^(a), —OC(═S)R^(a), —OC(═O)OR^(a),—OC(═O)N(R^(a))₂, —OS(═O)R^(a), —OS(═O)OR^(a), —OS(═O)N(R^(a))₂,—OS(═O)₂R^(a), —OS(═O)₂OR^(a), —OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃,—OSi(R^(a))₂(OR^(a)), —OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo,—N(R^(a))₂, —N═C(R^(a))₂, ═NR^(a), —NC, —NCO, —N₃, —NO₂,—NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a), —NR^(a)C(═O)N(R^(a))₂,—NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR^(a), —NR^(a)S(═O)N(R^(a))₂,—NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a), —NR^(a)S(═O)₂N(R^(a))₂,—SR^(a), —SCN, —S(═O)R^(a), —S(═O)OR^(a), —S(═O)N(R^(a))₂, —S(═O)₂R^(a),—S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂, —SeR^(a), halogen, —CN,—C(═NR^(a))R^(a), —C(═NR^(a))OR^(a), —C(═NR^(a))N(R^(a))₂, —C(═O)R^(a),—C(═O)OR^(a), —C(═O)SR^(a), —C(═S)OR^(a), or —C(═O)N(R^(a))₂; eachinstance of R^(S) is independently hydrogen or —OR^(a); each instance ofw is independently 0, 1, 2, 3, or 4; each instance of h is independently0, 1, 2, or 3; each instance of i is independently 0, 1, 2, or 3; eachinstance of R^(U) is independently hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted alkenyl, substitutedor unsubstituted alkynyl, substituted or unsubstitutedcarbocyclyl,substituted or unsubstitutedheterocyclyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, —OR^(a), —OCN,—OC(═O)R^(a), —OC(═S)R^(a), —OC(═O)OR^(a), —OC(═O)N(R^(a))₂,—OS(═O)R^(a), —OS(═O)OR^(a), —OS(═O)N(R^(a))₂, —OS(═O)₂R^(a),—OS(═O)₂OR^(a), —OS(═O)₂N(R^(a))₂, —OSi(R^(a))₃, —OSi(R^(a))₂(OR^(a)),—OSi(R^(a))(OR^(a))₂, —OSi(OR^(a))₃, oxo, —N(R^(a))₂, —N═C(R^(a))₂,═NR^(a), —NC, —NCO, —N₃, —NO₂, —NR^(a)C(═O)R^(a), —NR^(a)C(═O)OR^(a),—NR^(a)C(═O)N(R^(a))₂, —NR^(a)S(═O)R^(a), —NR^(a)S(═O)OR^(a),—NR^(a)S(═O)N(R^(a))₂, —NR^(a)S(═O)₂R^(a), —NR^(a)S(═O)₂OR^(a),—NR^(a)S(═O)₂N(R^(a))₂, —SR^(a), —SCN, —S(═O)R^(a), —S(═O)OR^(a),—S(═O)N(R^(a))₂, —S(═O)₂R^(a), —S(═O)₂OR^(a), —S(═O)₂N(R^(a))₂,—SeR^(a), halogen, —CN, —C(═NR^(a))R^(a), —C(═NR^(a))OR^(a),—C(═NR^(a))N(R^(a))₂, —C(═O)R^(a), —C(═O)OR^(a), —C(═O)SR^(a),—C(═S)OR^(a), or —C(═O)N(R^(a))₂; and each instance of R^(T) isindependently hydrogen, substituted or unsubstituted alkyl, substitutedor unsubstituted alkenyl, substituted or unsubstituted alkynyl,substituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, or substituted orunsubstituted heteroaryl.
 2. A hydroxylated polymer prepared byhydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst: i) one or more instances of afirst monomer, wherein each instance of the first monomer isindependently of the formula:

or salt thereof, wherein: each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring; each instance of Z is independentlyC(R^(P))₂ or 0; each instance of R^(P) is independently hydrogen,halogen, or substituted or unsubstituted, C₁₋₆ alkyl; and each instanceof

is independently a single bond or double bond; and ii) one or moreinstances of a second monomer, wherein each instance of the secondmonomer is of Formula (B):

or a salt thereof; wherein: each instance of Y is independently O orC(R^(Q))₂; each instance of R^(Q) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl; each instance of R^(K) isindependently hydrogen, halogen, substituted or unsubstituted, C₁₋₁₀alkyl, substituted or unsubstituted carbocyclyl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted aryl,substituted or unsubstituted heteroaryl, or —OR^(N); each instance ofR^(N) is independently hydrogen, substituted or unsubstituted acyl,substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, or anoxygen protecting group; each instance of j is independently 1, 2, or 3;and each instance of k is independently 0, 1, 2, or 3; wherein any twoinstances of the first monomer are the same as or different from eachother, and any two instances of the second monomer are the same as ordifferent from each other; and wherein the step of hydrolyzing thecopolymer comprises hydrolyzing one or more instances of the —O—Si bondsof the copolymer to form —OH.
 3. The functional oligomer or functionalpolymer of claim 1, wherein the functional oligomer or functional isprepared by a method comprising hydrolyzing a copolymer prepared by amethod comprising polymerizing in the presence of a metathesis catalyst:i) one or more instances of a first monomer, wherein each instance ofthe first monomer is of the formula:

or salt thereof; ii) one or more instances of a second monomer, whereineach instance of the second monomer is of the formula:

or a salt thereof; wherein: Y is O or C(R^(Q))₂; each instance of R^(Q)is independently hydrogen, halogen, or substituted or unsubstituted,C₁₋₆ alkyl; each instance of R^(K) is independently hydrogen, halogen,substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, or —OR^(N);each instance of R^(N) is independently hydrogen, substituted orunsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,substituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, substituted orunsubstituted heteroaryl, or an oxygen protecting group; j is 1, 2, or3; and k is 0, 1, 2, or 3; and iii) optionally one or more instances ofa third monomer; wherein any two instances of the first monomer are thesame as or different from each other, any two instances of the secondmonomer are the same as or different from each other, any two instancesof the third monomer are the same as or different from each other, andeach instance of the first monomer, the second monomer, and the thirdmonomer if present, is different from each other; and wherein the stepof hydrolyzing the copolymer comprises hydrolyzing one or more instancesof the —O—Si bonds of the copolymer to form —OH.
 4. The functionaloligomer or functional polymer of claim 1, wherein the functionaloligomer or functional polymer is prepared by a method comprisinghydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst: i) one or more instances of afirst monomer, wherein each instance of the first monomer is of theformula:

or salt thereof; ii) one or more instances of a second monomer, whereineach instance of the second monomer is of the formula:

or a salt thereof; and iii) optionally one or more instances of a thirdmonomer; wherein any two instances of the first monomer are the same asor different from each other, any two instances of the second monomerare the same as or different from each other, any two instances of thethird monomer are the same as or different from each other, and eachinstance of the first monomer, the second monomer, and the third monomerif present, is different from each other; and wherein the step ofhydrolyzing the copolymer comprises hydrolyzing one or more instances of

of the copolymer to form


5. A method of preparing a hydroxylated polymer of claim 2 comprisinghydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst: i) one or more instances of afirst monomer, wherein each instance of the first monomer isindependently of the formula:

or salt thereof, wherein: each instance of

is Ring B, wherein each instance of Ring B is independently asubstituted or unsubstituted, monocyclic carbocyclic ring, substitutedor unsubstituted, monocyclic heterocyclic ring, substituted orunsubstituted, monocyclic aryl ring, or substituted or unsubstituted,monocyclic heteroaryl ring; each instance of Z is independentlyC(R^(P))₂ or O; each instance of R^(P) is independently hydrogen,halogen, or substituted or unsubstituted, C₁₋₆ alkyl; and each instanceof

is independently a single bond or double bond; and ii) one or moreinstances of a second monomer, wherein each instance of the secondmonomer is of Formula (B):

or a salt thereof; wherein: each instance of Y is independently O orC(R^(Q))₂; each instance of R^(Q) is independently hydrogen, halogen, orsubstituted or unsubstituted, C₁₋₆ alkyl; each instance of R^(K) isindependently hydrogen, halogen, substituted or unsubstituted, C₁₋₁₀alkyl, substituted or unsubstituted carbocyclyl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted aryl,substituted or unsubstituted heteroaryl, or —OR^(N); each instance ofR^(N) is independently hydrogen, substituted or unsubstituted acyl,substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, or anoxygen protecting group; each instance of j is independently 1, 2, or 3;and each instance of k is independently 0, 1, 2, or 3; wherein any twoinstances of the first monomer are the same as or different from eachother, and any two instances of the second monomer are the same as ordifferent from each other; and wherein the step of hydrolyzing thecopolymer comprises hydrolyzing one or more instances of the —O—Si bondsof the copolymer to form —OH.
 6. A method of preparing a functionaloligomer or functional polymer of claim 3 comprising hydrolyzing acopolymer prepared by a method comprising polymerizing in the presenceof a metathesis catalyst: i) one or more instances of a first monomer,wherein each instance of the first monomer is of the formula:

or salt thereof; ii) one or more instances of a second monomer, whereineach instance of the second monomer is of the formula:

or a salt thereof; and iii) optionally one or more instances of a thirdmonomer; wherein any two instances of the first monomer are the same asor different from each other, any two instances of the second monomerare the same as or different from each other, any two instances of thethird monomer are the same as or different from each other, and eachinstance of the first monomer, the second monomer, and the third monomerif present, is different from each other; and wherein the step ofhydrolyzing the copolymer comprises hydrolyzing one or more instances ofthe —O—Si bonds of the copolymer to form —OH.
 7. A method of preparing afunctional oligomer or functional polymer of claim 4 comprisinghydrolyzing a copolymer prepared by a method comprising polymerizing inthe presence of a metathesis catalyst: i) one or more instances of afirst monomer, wherein each instance of the first monomer is of theformula:

or salt thereof; ii) one or more instances of a second monomer, whereineach instance of the second monomer is of the formula:

or a salt thereof; and iii) optionally one or more instances of a thirdmonomer; wherein any two instances of the first monomer are the same asor different from each other, any two instances of the second monomerare the same as or different from each other, any two instances of thethird monomer are the same as or different from each other, and eachinstance of the first monomer, the second monomer, and the third monomerif present, is different from each other; and wherein the step ofhydrolyzing the copolymer comprises hydrolyzing one or more instances of

of the copolymer to form

8-19. (canceled)
 20. A compound of Formula (B1):

or a salt thereof; wherein: Y is O or C(R^(Q))₂; each instance of R^(Q)is independently hydrogen, halogen, or substituted or unsubstituted,C₁₋₆ alkyl; each instance of R^(K) is independently hydrogen, halogen,substituted or unsubstituted, C₁₋₁₀ alkyl, substituted or unsubstitutedcarbocyclyl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted aryl, substituted or unsubstituted heteroaryl, or —OR^(N);each instance of R^(N) is independently hydrogen, substituted orunsubstituted acyl, substituted or unsubstituted, C₁₋₁₀ alkyl,substituted or unsubstituted carbocyclyl, substituted or unsubstitutedheterocyclyl, substituted or unsubstituted aryl, substituted orunsubstituted heteroaryl, or an oxygen protecting group; j is 1, 2, or3; and k is 0, 1, 2, or 3; provided that the compound is not of theformula:

21-24. (canceled)
 25. A copolymer prepared by a method comprisingpolymerizing: one or more instances of a first monomer; one or moreinstances of a second monomer, wherein the second monomer is a compoundof claim 20, or a salt thereof; and optionally one or more instances ofa third monomer; wherein any two instances of the first monomer are thesame as or different from each other, any two instances of the secondmonomer are the same as or different from each other, any two instancesof the third monomer are the same as or different from each other, andeach instance of the first monomer, the second monomer, and the thirdmonomer if present, is different from each other; in the presence of ametathesis catalyst.
 26. A method of preparing a copolymer of claim 25comprising polymerizing: one or more instances of a first monomer; oneor more instances of a second monomer, wherein the second monomer is acompound of claim 20, or a salt thereof; and optionally one or moreinstances of a third monomer; wherein any two instances of the firstmonomer are the same as or different from each other, any two instancesof the second monomer are the same as or different from each other, anytwo instances of the third monomer are the same as or different fromeach other, and each instance of the first monomer, the second monomer,and the third monomer if present, is different from each other; in thepresence of a metathesis catalyst. 27-30. (canceled)
 31. The functionaloligomer or functional polymer of claim 1, wherein each instance of thelinear units is of the formula:

32-33. (canceled)
 34. The functional oligomer or functional polymer ofclaim 1, wherein each instance of the linear units is of the formula:

35-36. (canceled)
 37. The functional oligomer or functional polymer ofclaim 1, wherein at least one instance of the functional units isindependently of the formula:

38-42. (canceled)
 43. The functional oligomer or functional polymer ofclaim 1, wherein at least one instance of the functional units isindependently of the formula:

44-85. (canceled)
 86. A composition comprising: a hydroxylated polymerof claim 2; and optionally an excipient.
 87. A kit comprising: ahydroxylated polymer of claim 2; and instructions for using thehydroxylated polymer.
 88. A conjugate prepared by reacting ahydroxy-reacting substance with a hydroxylated polymer of claim 2,wherein hydroxy-reacting substance comprises at least one instance of ahydroxy-reacting moiety.
 89. A method of preparing a conjugatecomprising reacting a hydroxy-reacting substance with a hydroxylatedpolymer of claim
 2. 90-96. (canceled)
 97. A composition comprising: aconjugate of claim 88; and optionally an excipient.
 98. A kitcomprising: a conjugate of claim 88; and instructions for using theconjugate.